Linear module sliding table positioning device and calibration method

Abstract

The linear module sliding table positioning device comprises a sliding frame, a linear module is arranged on the sliding frame, a sliding table is arranged on the linear module in a sleeving mode, a laser ranging module is arranged on one side of the sliding table, and a first calibration range finder and a second calibration range finder are arranged on the two sides of the sliding frame respectively. When the sliding table moves to a position where the sawteeth are relatively low, recording the value of the calibrated distance measuring instrument as x0 at the moment, and recording distance data y0 between the laser distance measuring module and the distance measuring reflecting plate at the same time; the sliding table moves rightwards by a certain distance, the corresponding calibration range finder value x1 and the distance y1 between the laser ranging module and the ranging reflecting plate are recorded, the linear module sliding table positioning device and the calibration method achieve the purposes of high range and high precision at the same time, and the measurement precision is not affected by the length of the linear module.

Description

Technical Field

[0001] The present invention relates to the field of linear module slide positioning devices and calibration methods, and in particular to a linear module slide positioning device and calibration method. Background Art

[0002] At present, in linear modules, in order to obtain the actual position of the slide, the following methods are usually used: 1. Install an encoder on the motor shaft of the linear module (or one of the shafts of the linear module); however, the gap between the motor shaft and the synchronous belt or lead screw, the tension deformation of the synchronous belt, etc. will affect the position accuracy of the slide; 2. Install a wire position sensor on the slide to obtain the slide position, but the wire also has problems such as deformation and easy damage at high speed; 3. When directly using laser ranging to measure the slide position, it is difficult to meet both the range and accuracy.

[0003] Therefore, it is necessary to provide a new linear module slide positioning device and calibration method to solve the above technical problems. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a linear module slide positioning device and a calibration method that are easy to peel off.

[0005] The linear module slide positioning device and calibration method provided by the present invention include a slide frame, a linear module is arranged on the slide frame, a slide is sleeved on the linear module, a laser ranging module is arranged on one side of the slide, and a first calibration rangefinder and a second calibration rangefinder are arranged on both sides of the slide frame respectively;

[0006] The slide moves to a position where the sawtooth is lower, and the calibration value of the rangefinder is recorded as x0, and the distance data y0 between the laser ranging module and the ranging reflector is recorded; the slide moves to the right by a certain distance, and the corresponding calibration value x1 of the rangefinder and the distance y1 between the laser ranging module and the ranging reflector are recorded;

[0007] During calibration, it is necessary to ensure that at least one set of calibration data is collected on each ranging reflector. By moving the slide to the right, the data on other sawtooth on the reflector can be obtained (x2, y2), (x3, y3), (x4, y4). Let (x0, y0) and (x1, y1) be the two sets of data collected on the ranging reflector, and the calibration data (a1, b1) of this ranging reflector can be obtained by the following formula:

[0008] Formula 1:

[0009] Wherein a1 represents the slope of each sawtooth of the ranging reflector, and b1 represents the reference distance of each sawtooth relative to the first calibration rangefinder.

[0010] When more than two pieces of data are collected from the same sawtooth on the ranging reflector during calibration, as shown in the following formula 2, the least squares method can be used to fit to obtain more accurate calibration data (a1, b1);

[0011] Formula 2:

[0012] set up The calibration calculation result of this ranging reflector is shown in the following formula 3:

[0013] Formula 3: B = (A T *A) -1 *A T *C

[0014] By analogy, the calibration data (a2, b2), (a3, b3), ... of each other inclined surface on the laser ranging reflector are obtained.

[0015] In order to achieve the effect of improving the calibration accuracy through calibration in multiple directions, the present invention provides a linear module slide positioning device and a calibration method. Preferably, when the first calibration rangefinder and the second calibration rangefinder are calibrated, the data sampled from the laser ranging module when calibrating on the ranging reflector is [y0, y1, ..., y n ], and the corresponding data of the first calibration rangefinder is [x0,x1,…,x n ], the data of the second calibration rangefinder (7) is [z0,z1,…,z n ]. Then the calibration calculation is as shown in the following formula: Formula 4

[0016] Wherein a1 represents the slope of each sawtooth of the ranging reflector, b1 represents the reference distance of each sawtooth relative to the first calibration rangefinder, and c1 represents the position difference between the slide and the first calibration rangefinder and the second calibration rangefinder.

[0017] In order to facilitate the positioning of the slide, the slide is moved to the vicinity of the first reflector at the far left end for example to measure the slide position. At this time, the data y of the laser rangefinder module is directly read, and then the calibration data (a1, b1) of the first reflector is used to calculate the actual position x of the slide through the formula x = a1*y+b1, and the calibration data (a2, b2) of the second reflector is called and the slide position x is calculated through x = a2*y+b2. Finally, the calculation formula of the slide position can be directly recorded as shown in the following formula.

[0018] x=a n *y+b n

[0019] Where n represents the number of jumps of the laser rangefinder data when the slide moves rightward from the starting point, (a n ,b n ) represents the calibration parameters of the nth anti-aliasing block.

[0020] In order to achieve the effect of analyzing the accuracy, the teeth of the ranging reflector have an angle. Assuming the angle of ∠CAB is θ, the accuracy of the laser ranging module is d0, and the measurement accuracy of this solution is d, the following formula is obtained:

[0021] d=d0*tan(θ)

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The linear module slide positioning device and calibration method can simultaneously meet high range and high precision, and the measurement accuracy is not affected by the length of the linear module. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic structural diagram of a preferred embodiment of the linear module slide positioning device and calibration method provided by the present invention;

[0025] Figure 2 for Figure 1 Schematic diagram of laser ranging reflector and other shapes and structures shown;

[0026] Figure 3 for Figure 2 The schematic diagram of the distance measuring reflector structure with higher measurement accuracy is shown;

[0027] Figure 4 It is a calibration schematic diagram shown in the present invention;

[0028] Figure 5 It is a schematic diagram of the structures of the first calibration rangefinder and the second calibration rangefinder of the present invention.

[0029] Numbers in the figure: 1, sliding frame; 2, linear module; 3, slide table; 4, laser ranging module; 5, ranging reflector; 6, first calibrated rangefinder; 7, second calibrated rangefinder. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0031] Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 ,in Figure 1 A schematic structural diagram of a preferred embodiment of the linear module slide positioning device and calibration method provided by the present invention; Figure 2 for Figure 1 Schematic diagram of laser ranging reflector and other shapes and structures shown; Figure 3 for Figure 2 The schematic diagram of the distance measuring reflector structure with higher measurement accuracy is shown; Figure 4 It is a calibration schematic diagram shown in the present invention; Figure 5 The figure is a schematic diagram of the structure of the first calibration rangefinder and the second calibration rangefinder of the present invention. The linear module slide positioning device and calibration method include a slide frame 1, a linear module 2 is arranged on the slide frame 1, a slide 3 is sleeved on the linear module 2, a laser ranging module 4 is arranged on one side of the slide 3, and a first calibration rangefinder 6 and a second calibration rangefinder 7 are arranged on both sides of the slide frame 1 respectively;

[0032] The slide 3 moves to the lower position of the sawtooth, and the calibration value of the rangefinder is recorded as x0, and the distance data y0 between the laser ranging module 4 and the ranging reflector 5 is recorded; the slide 3 moves to the right for a certain distance, and the corresponding calibration value x1 of the rangefinder and the distance y1 between the laser ranging module 4 and the ranging reflector 5 are recorded;

[0033] During calibration, it is necessary to ensure that at least two sets of calibration data are collected on each ranging reflector 5. By moving the slide 3 to the right, the data (x2, y2), (x3, y3), (x4, y4) on other sawtooth on the reflector can be obtained. Let (x0, y0) and (x1, y1) be the two sets of data collected on the ranging reflector 5, and the calibration data (a1, b1) of this ranging reflector 5 can be obtained by the following formula:

[0034] Formula 1:

[0035] Wherein a1 represents the slope of each sawtooth of the ranging reflector 5 , and b1 represents the reference distance of each sawtooth relative to the first calibration rangefinder 6 .

[0036] When more than two pieces of data are collected from the same sawtooth on the ranging reflector 5 during calibration, as shown in the following formula 2, the least squares method can be used to fit to obtain more accurate calibration data (a1, b1);

[0037] Formula 2:

[0038] set up The calibration calculation result of the ranging reflector 5 is as shown in the following formula 3:

[0039] Formula 3: B = (A T *A) -1 *A T *C

[0040] By analogy, the calibration data (a2, b2), (a3, b3), ... of each other inclined surface on the laser ranging reflector 5 are obtained.

[0041] It should be noted that: Figure 1 The measuring range of the laser distance measuring module 4 only needs to be smaller than the distance between the laser distance measuring module 4 and the distance measuring reflector 5. The length of the distance measuring reflector 5 only needs to cover the motion range of the slide 3.

[0042] The laser distance measuring module 4 is mounted on the slide 3, and the ranging reflector 5 has a sawtooth reflective surface. Figure 1 In addition to the right-angle shapes shown, there are also Figure 2 The shape shown in the figure, wherein the sawtooth angle of the ranging reflector 5 is not fixed, and can be any angle according to different precisions. When the precision requirement is high, the angle of ∠CAB needs to be larger, that is, the reflection surface AC is steeper; when the precision requirement is low, the angle of ∠CAB can be smaller, that is, the inclination angle of the reflection surface AC is smaller, such as Figure 4 The sensor value used to record the position of the calibrated slide 3 is represented by x, and the value of the calibrated rangefinder used to record the position of the slide is represented by y. During calibration, the slide 3 needs to be moved to the starting position to be calibrated, and each sawtooth on the ranging reflector 5 is calibrated from left to right.

[0043] In the specific implementation process, Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, when the first calibration rangefinder 6 and the second calibration rangefinder 7 are calibrated, the data sampled from the laser ranging module 4 when calibrated on the ranging reflector 5 is [y0, y1, ..., y n ], and the corresponding data of the first calibration rangefinder 6 is [x0, x1, ..., x n ], the data of the second calibration rangefinder 7 is [z0,z1,…,z n ]. Then the calibration calculation is as shown in the following formula

[0044] Formula 4

[0045] Wherein a1 represents the slope of each sawtooth of the ranging reflector 5 , b1 represents the reference distance of each sawtooth relative to the first calibration rangefinder 6 , and c1 represents the position difference between the slide 3 and the first calibration rangefinder 6 and the second calibration rangefinder 7 .

[0046] It should be noted that: since the measurement accuracy of the laser ranging module 4 decreases with the increase of the measurement range, when a large-range and high-precision measurement is required, it is only necessary to reduce the height of the laser ranging reflector to use a laser rangefinder with a smaller range and higher precision, thereby ensuring the large-range and high-precision measurement requirements, such as Figure 3 shown.

[0047] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the slide is moved to the vicinity of the first reflector at the far left end for example to measure the slide position. At this time, the data y of the laser ranging module is directly read, and then the calibration data (a1, b1) of the first reflector is used to calculate the actual position x of the slide through the formula x=a1*y+b1, and the calibration data (a2, b2) of the second reflector is called and the slide position x is calculated through x=a2*y+b2. Finally, the calculation formula of the slide position can be directly recorded as shown in the following formula.

[0048] x=a n *y+b n

[0049] Where n represents the number of jumps of the laser rangefinder data when the slide moves rightward from the starting point, (a n ,b n ) represents the calibration parameters of the nth anti-aliasing block.

[0050] The working principle of a linear module slide positioning device and calibration method provided by the present invention is as follows:

[0051] When starting, the slide 3 needs to be moved to the designated distance measuring reflector 5 position. The following example takes the slide 3 moving to the vicinity of the first distance measuring reflector 5 at the far left end when starting to measure the position of the slide 3. At this time, the data y of the laser distance measuring module 4 is directly read, and then the actual position x of the slide 3 is calculated by the formula x=a1*y+b1 using the calibration data (a1, b1) of the first distance measuring reflector 5. When the slide 3 moves to the right, the distance between the laser distance measuring module and the distance measuring reflector 5 is closer, so the read y value will gradually decrease.

[0052] As the slide 3 moves to the right, when the laser distance sensor moves to the position of the second distance measuring reflector 5, its data y will suddenly decrease, and the laser distance meter will produce a non-connected position jump. That is, in the present invention, this data jump of the laser distance meter is used to obtain the calibration parameters.

[0053] Since the laser rangefinder has a position jump, the calibration data (a2, b2) of the second rangefinder reflector 5 should be called and the position x of the slide 3 should be calculated by x=a2*y+b2. Finally, the calculation formula of the position of the slide 3 can be directly recorded as shown in the following formula.

[0054] x=a n *y+b n

[0055] Where n represents the number of jumps of the laser rangefinder data when the slide 3 moves rightward from the starting point, (a n ,b n ) represents the calibration parameters of the nth anti-aliasing block.

[0056] Similarly, when the slide 3 moves to the left, the y value of the laser distance sensor on the same reflector will gradually increase. When the y value suddenly increases and jumps, it means that the laser distance sensor moves to a reflector further to the left, and the corresponding calibration data is called to calculate the slide position.

[0057] by Figure 1 For example, let the angle of ∠CAB be θ, the accuracy of the laser ranging module 4 be d0, and the measurement accuracy of this solution be d, then we have

[0058] d=d0*tan(θ)

[0059] From the formula, it can be seen that when the angle ∠CAB of each sawtooth of the reflector is 45 degrees, the measurement accuracy of the linear module 2 is equal to the measurement accuracy of the laser rangefinder. When the angle of ∠CAB increases and becomes steeper, the measurement accuracy of the linear module 2 is greater than the measurement accuracy of the laser rangefinder. Conversely, when the angle of ∠CAB decreases and becomes flatter, the measurement accuracy of the linear module 2 is less than the measurement accuracy of the laser rangefinder.

[0060] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A linear module slide positioning device and calibration method, characterized in that: The invention comprises a slide frame (1), wherein a linear module (2) is arranged on the slide frame (1), a slide table (3) is sleeved on the linear module (2), a laser distance measurement module (4) is arranged on one side of the slide table (3), and a first calibration distance meter (6) and a second calibration distance meter (7) are respectively arranged on both sides of the slide frame (1).

2. The calibration method of the linear module slide positioning device according to claim 1: The slide table (3) moves to a position where the saw teeth are lower, and the calibration rangefinder value x0 is recorded at this time, and the distance data y0 between the laser ranging module (4) and the ranging reflector (5) is recorded; the slide table (3) moves to the right by a certain distance, and the corresponding calibration rangefinder value x1 and the distance y1 between the laser ranging module (4) and the ranging reflector (5) are recorded; During calibration, it is necessary to ensure that at least two sets of calibration data are collected on each ranging reflector (5). By moving the slide table (3) to the right in this way, data (x2, y2), (x3, y3), (x4, y4) on other saw teeth on the reflector can be obtained. Assume that (x0, y0) and (x1, y1) are two sets of data collected on the ranging reflector (5), and the calibration data (a1, b1) of this ranging reflector (5) can be obtained by the following formula: Formula 1: Wherein a1 represents the slope of each sawtooth of the ranging reflector plate (5), and b1 represents the reference distance of each sawtooth relative to the first calibration distance meter (6). When more than two pieces of data are collected from the same sawtooth on the ranging reflector (5) during calibration, as shown in the following formula 2, the least squares method can be used to fit to obtain more accurate calibration data (a1, b1); Formula 2: set up The calibration calculation result of this distance measuring reflector (5) is shown in the following formula 3: Formula 3: B = (A T *A) -1 *A T *C By analogy, the calibration data (a2, b2), (a3, b3), ... of each other inclined surface on the laser ranging reflector (5) are obtained; When the first calibration rangefinder (6) and the second calibration rangefinder (7) are calibrated, the data sampled from the laser distance measurement module (4) when calibrated on the distance measurement reflection plate (5) is [y0, y1, ..., y n ], and the corresponding data of the first calibration rangefinder (6) is [x0, x1, …, x n ], the data of the second calibration rangefinder (7) is [z0,z1,…,z n ]. Then the calibration calculation is as shown in the following formula: Formula 4 Wherein a1 represents the slope of each sawtooth of the ranging reflector plate (5), b1 represents the reference distance of each sawtooth relative to the first calibration distance meter (6), and c1 represents the position difference between the slide table (3) and the first calibration distance meter (6) and the second calibration distance meter (7).

3. According to the calibration method of the linear module slide positioning device of claim 2, the slide position is measured by taking the slide moving to the vicinity of the first reflector at the leftmost end as an example. At this time, the data y of the laser ranging module is directly read and then the actual position x of the slide is calculated by the formula x=a1*y+b1 using the calibration data (a1, b1) of the first reflector. The calibration data (a2, b2) of the second reflector is called and the slide position x is calculated by x=a2*y+b2. Finally, the calculation formula of the slide position can be directly recorded as shown in the following formula; x=a n *y+b n Where n represents the number of jumps of the laser rangefinder data when the slide moves rightward from the starting point, (a n ,b n ) represents the calibration parameters of the nth anti-aliasing block.

4. According to the calibration method of the linear module slide positioning device of claim 2, the teeth of the ranging reflector (5) have an angle, assuming that the angle of ∠CAB is θ, the accuracy of the laser ranging module is d0, and the measurement accuracy of the present solution is d, then the following formula is obtained: d = d0*tan(θ).

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