Calibration method and device for door closing speed measuring instrument

Abstract

The invention relates to a calibration method and device for a door closing speed measuring instrument. The calibration method comprises the following steps: S1, hanging the door closing speed measuring instrument to a preset height; s2, whether the door closing speed measuring instrument reaches a preset height or not is detected, and adjustment is conducted according to a detection result; s3, the door closing speed measuring instrument is subjected to counterweight, so that the gravity center is located on the central axis of the handle; s4, enabling the door closing speed measuring instrument to perform free falling motion, and recording a speed value v; and S5, the steps S1-S4 are repeated i times, i speed values v are obtained, the i speed values v are calculated to obtain an average speed value # imgabs0 #, a theoretical speed vt is obtained according to a free falling body speed calculation formula # imgabs1 #, an indicating value error delta vi of the door closing speed measuring instrument is obtained through calculation according to a formula # imgabs2 #, g is the gravitational acceleration, and h is the preset height. According to the invention, accurate calibration of the door closing speed measuring instrument is realized, and the method belongs to the technical field of speed measuring instrument calibration.

Description

Technical Field

[0001] The present invention relates to the technical field of speedometer calibration, and particularly relates to a calibration method and device for a door closing speed measuring instrument. Background Art

[0002] With the rapid development of the automotive industry, people's requirements for the quality of automobiles are getting higher and higher. The door closing speed of an automobile is an important technical indicator in automobile manufacturing and is related to the safety performance of the automobile.

[0003] The door closing speed measuring instrument is a wireless device with an in-built acceleration sensor. Its working principle is to calculate the speed during the movement process by integrating the acceleration of the device over time during the movement. The existing method for calibrating the door closing speed measuring instrument is to lift the door closing speed measuring instrument to a corresponding height and let it free fall, and by comparing the theoretical speed value and the speed value displayed by the door closing speed measuring instrument, the difference between the two is the error value of the door closing speed measuring instrument. However, the above calibration method has the following disadvantages: 1. The method of free fall does not consider the situation of inclination when the door closing speed measuring instrument is lifted to the corresponding height, and the influence of inclination on the height has a large measurement uncertainty. 2. When using the method of free fall, the center of gravity of the door closing speed measuring instrument itself is not on the handle axis, and it cannot ensure a stable landing, and abnormal values will appear in the data. Summary of the Invention

[0004] Aiming at the technical problems existing in the prior art, the object of the present invention is: to provide a calibration method for a door closing speed measuring instrument, which makes the center of gravity of the door closing speed measuring instrument located on the central axis of its handle before the free fall movement, realizes accurate calibration of the door closing speed measuring instrument, and solves the problem that when using the existing free fall method, the center of gravity of the door closing speed measuring instrument itself is not on the handle axis, cannot ensure a stable landing, and abnormal values will appear in the data.

[0005] Another object of the present invention is: to provide a calibration device for a door closing speed measuring instrument, which makes the center of gravity of the door closing speed measuring instrument located on the central axis of its handle by setting a counterweight container, realizes accurate calibration of the door closing speed measuring instrument, and solves the problem that when using the existing free fall method, the center of gravity of the door closing speed measuring instrument itself is not on the handle axis, cannot ensure a stable landing, and abnormal values will appear in the data.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A calibration method for a door closing speed measuring instrument, the calibration method includes the following steps:

[0008] S1: Hang the door closing speed measuring instrument to a preset height;

[0009] S2: Detect whether the closing speed measuring instrument reaches the preset height. If it does not reach the preset height, adjust the closing speed measuring instrument until it reaches the preset height;

[0010] S3: Weigh the closing speed measuring instrument so that the center of gravity of the closing speed measuring instrument is on the central axis of its handle;

[0011] S4: Let the closing speed measuring instrument perform free fall motion, and record the speed value v when the closing speed measuring instrument reaches the falling position;

[0012] S5: Repeat steps S1 - S4 for i times to obtain i speed values v when the closing speed measuring instrument reaches the falling position, and calculate the average speed value when the i closing speed measuring instruments reach the falling position According to the free - fall speed calculation formula Obtain the theoretical speed v when the closing speed measuring instrument reaches the falling position t , according to the formula:

[0013]

[0014] Calculate the indication error δv of the closing speed measuring instrument at the preset height i , where g is the acceleration due to gravity and h is the preset height.

[0015] As an option, in step S1, the closing speed measuring instrument is adsorbed and suspended at the preset height by an electromagnetic adsorption component.

[0016] As an option, in step S2, a grating ruler is used to detect whether the closing speed measuring instrument reaches the preset height.

[0017] As an option, in step S2, an inclination sensor is also used to detect whether the closing speed measuring instrument is in a horizontal state.

[0018] As an option, in step S3, the weighing method is: connect a weighing container to the closing speed measuring instrument, and add or subtract steel balls in the weighing container to weigh the closing speed measuring instrument.

[0019] The calibration device for the closing speed measuring instrument includes a grating ruler, a mainframe, a controller, a weighing container and a crossbeam. The grating ruler is vertically arranged on the mainframe to detect the height of the crossbeam. The crossbeam can move vertically relative to the grating ruler. The crossbeam is used to hang the closing speed measuring instrument to be calibrated. The weighing container is used to connect with the closing speed measuring instrument to be calibrated so that its center of gravity is on the central axis of its handle; there is a falling area for the closing speed measuring instrument on the mainframe, and the controller is used to control the vertical movement of the crossbeam.

[0020] As a preference, a driving motor is installed on the main machine. The driving motor is connected with a lead screw assembly. The driving motor drives the lead screw assembly to move the slider of the lead screw assembly in the vertical direction. A rotating motor is provided on the slider of the lead screw assembly. The rotating motor moves in the vertical direction along with the slider of the lead screw assembly. The output shaft of the rotating motor is horizontally arranged. The cross beam is connected with the output shaft of the rotating motor to rotate along with the output shaft of the rotating motor.

[0021] As a preference, the calibration device further includes an inclination sensor. The inclination sensor is arranged on the cross beam to detect whether the cross beam is horizontal.

[0022] As a preference, a leveling mechanism is provided on the main machine to keep the dropping area horizontal. The leveling mechanism includes an X-axis electronic level, a Y-axis electronic level and a horizontal adjusting nut. Both the X-axis electronic level and the Y-axis electronic level are arranged on the main machine. The horizontal adjusting nut is arranged at the bottom of the main machine.

[0023] As a preference, the calibration device further includes a vacuum cup. The vacuum cup is used to connect the closing speed measuring instrument to be calibrated. A dropping floor is provided on the main machine. The dropping floor cooperates with the vacuum cup to protect the closing speed measuring instrument to be calibrated.

[0024] Generally speaking, the present invention has the following advantages:

[0025] 1. The calibration method of the present invention weights the closing speed measuring instrument to be calibrated before the free fall motion, so that the center of gravity of the closing speed measuring instrument to be calibrated is located on the central axis of its handle, thus avoiding the problem that the existing free fall detection method cannot ensure the stable landing of the closing speed measuring instrument and abnormal values will appear in the data of the closing speed measuring instrument.

[0026] 2. The calibration device of the present invention realizes weighting the closing speed measuring instrument to be calibrated by setting a weighting container connected with the closing speed measuring instrument to be calibrated, so that the center of gravity of the closing speed measuring instrument to be calibrated is located on the central axis of its handle, thus avoiding the problem that the existing free fall detection method cannot ensure the stable landing of the closing speed measuring instrument and abnormal values will appear in the data of the closing speed measuring instrument. Description of the Drawings

[0027] Figure 1 It is a flowchart of a calibration method for a closing speed measuring instrument.

[0028] Figure 2 It is a schematic diagram of a calibration device for a closing speed measuring instrument.

[0029] Among them, 1 is a grating ruler, 2 is a rotating motor, 3 is a driving motor, 4 is a controller, 5 is an electromagnetic suction cup, 6 is an inclination sensor, 7 is a crossbeam, 8 is a connecting steel ball, 9 is a counterweight container, 10 is a closing speed measuring instrument, 11 is a vacuum cup, and 12 is a falling floor; 3-1 is an X-axis electronic level, and 3-2 is a horizontal adjustment nut. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below in conjunction with specific implementation methods.

[0031] Embodiment 1

[0032] like Figure 1 As shown, this embodiment provides a calibration method for a door closing speed measuring instrument, and the calibration method comprises the following steps:

[0033] S1: Hang the door closing speed measuring instrument to a preset height; illustratively, a beam that can move in the vertical direction is provided, and then an electromagnetic suction cup is provided on the beam, and a controller is used to control the electromagnetic suction cup to magnetically attract the door closing speed measuring instrument, so that the door closing speed measuring instrument is suspended on the beam, and then the controller controls the beam to move in the vertical direction until the beam reaches a preset height and stops. The movement of the beam in the vertical direction can be driven by a drive motor to drive the screw assembly to drive the beam to move in the vertical direction, and the controller controls the drive motor to open and close to control the beam. In addition, before calibration, it is necessary to adjust the screw assembly to be vertically set and the beam to be horizontally connected to the screw assembly.

[0034] S2: Detect whether the door closing speed measuring instrument reaches the preset height. If it does not reach the preset height, adjust the door closing speed measuring instrument until it reaches the preset height. Exemplarily, the position of the beam is detected by a grating ruler. If the grating ruler detects that the height of the beam does not reach the preset height, the controller controls the drive motor to drive the screw assembly, and the screw assembly drives the beam to move in the vertical direction until the beam reaches the preset height.

[0035] S3: counterweight the door closing speed measuring instrument so that the center of gravity of the door closing speed measuring instrument is located on the central axis of its handle; illustratively, counterweight is counterweighted by a suspension method, firstly a counterweight object (such as the configuration container described below) is connected and fixed to the door closing speed measuring instrument, and then the door closing speed measuring instrument is connected to an electromagnetic suction cup, and counterweight is achieved by increasing or decreasing steel balls so that the center of gravity of the door closing speed measuring instrument is located on the central axis of its handle.

[0036] S4: Let the door closing speed measuring instrument perform free fall motion, and record the speed value v when the door closing speed measuring instrument reaches the drop position; Exemplarily, before performing the free fall motion, the controller controls the crossbeam to descend until the vacuum cup fits the surface of the drop position, zeros the electrical components such as the controller and the grating scale, and then the controller controls the crossbeam to rise to a preset height and then performs the free fall motion.

[0037] S5: Repeat steps S1 - S4 for i times to obtain i speed values v when the door closing speed measuring instrument reaches the drop position, and calculate the average speed value when the i door closing speed measuring instruments reach the drop position. According to the free fall speed calculation formula Obtain the theoretical speed v when the door closing speed measuring instrument reaches the drop position. t , according to the formula:

[0038]

[0039] Calculate the indication error δv of the door closing speed measuring instrument at the preset height. i , where g is the acceleration due to gravity and h is the preset height.

[0040] The calibration method of this embodiment utilizes the principle of free fall motion. By calculating the comparison between the theoretical speed of the door closing speed measuring instrument falling at a fixed height and the speed displayed after the door closing speed measuring instrument falls, and calculating the difference between the two, the indication error of the door closing speed measuring instrument can be obtained. However, considering that in the existing method, when using the free fall method, the center of gravity of the door closing speed measuring instrument is not on the handle axis, and it cannot ensure a stable landing, and abnormal values will appear in the data; Therefore, the calibration method of this embodiment weights the door closing speed measuring instrument before it performs free fall motion, so that the center of gravity of the door closing speed measuring instrument is on the central axis of its handle, avoiding the problems existing in the existing calibration method and achieving precise calibration of the door closing speed measuring instrument.

[0041] In some embodiments, in step S1, the door closing speed measuring instrument is adsorbed and suspended at a preset height through an electromagnetic adsorption component. In this embodiment, the electromagnetic adsorption component uses an electromagnetic chuck. Considering that the door closing speed measuring instrument suspended at a preset height for free fall motion can only be affected by gravity, therefore, choosing electromagnetic chuck adsorption can avoid providing external force when releasing the door closing speed measuring instrument, resulting in interference with the free fall motion of the door closing speed measuring instrument. By demagnetizing the electromagnetic chuck, the door closing speed measuring instrument is only affected by gravity, ensuring the accuracy of calibration.

[0042] In some embodiments, in step S2, it is detected whether the door closing speed measuring instrument reaches a preset height through a grating scale. A high-precision grating scale is adopted, with a measuring range of (0 - 1000) mm, and the indication error ≤ ±(0.25 + L / 1000) μm (where: L is the measured length, unit: mm), and it is set perpendicular to the dropping position. It can move following the movement of the door closing speed measuring instrument in the vertical direction, so as to accurately measure the height value where the door closing speed measuring instrument is located, and thus can accurately obtain the theoretical speed value after the door closing speed measuring instrument drops.

[0043] In some embodiments, in step S2, it is also detected whether the door closing speed measuring instrument is in a horizontal state through an inclination sensor. The indication error of the inclination sensor ≤ ±0.005°, and the absolute zero point is used during use. Exemplarily, considering that the crossbeam where the door closing speed measuring instrument is suspended may be inclined, the height of the door closing speed measuring instrument may be slightly higher or lower due to the inclination of the crossbeam, so there is an error between the height detected by the grating scale and the actual height of the door closing speed measuring instrument, and thus there is a deviation in the theoretical speed value calculated after the door closing speed measuring instrument drops. Therefore, it is detected whether the structure for suspending the door closing speed measuring instrument is horizontal through the inclination sensor, so as to know whether the door closing speed measuring instrument is in a horizontal state, avoid the above problems, and further ensure that the calibration method in this embodiment can accurately calibrate the door closing speed measuring instrument.

[0044] In some embodiments, in step S3, the method of adding counterweight is as follows: the door closing speed measuring instrument is connected to a counterweight container, and the counterweight of the door closing speed measuring instrument is realized by adding or reducing steel balls in the counterweight container. In this embodiment, the counterweight of the door closing speed measuring instrument is realized by using a counterweight container and steel balls with known masses, and non-elastic objects can also be arranged in the counterweight container.

[0045] Embodiment 2

[0046] Such as Figure 2As shown in the figure, a calibration device for a closing speed measuring instrument 10 provided in this embodiment includes a grating scale 1, a mainframe, a controller 4, a counterweight container 9, and a crossbeam 7. The grating scale 1 is vertically arranged on the mainframe to detect the height of the crossbeam 7. The crossbeam 7 can move relative to the grating scale 1 in the vertical direction. The crossbeam 7 is used to hang the closing speed measuring instrument 10 to be calibrated. The counterweight container 9 is used to be connected to the closing speed measuring instrument 10 to be calibrated so that its center of gravity is located on the central axis of its handle. There is a dropping area of the closing speed measuring instrument 10 on the mainframe. The controller 4 is used to control the crossbeam 7 to move in the vertical direction. The grating scale 1 in this embodiment adopts a high-precision grating scale 1 with a measuring range of (0 - 1000) mm and an indication error ≤ ±(0.25 + L / 1000) μm (where: L is the measured length, unit: mm), and it is set perpendicular to the dropping position. It can move along with the crossbeam 7 moving in the vertical direction, so as to accurately measure the height value where the closing speed measuring instrument 10 is located, and thus can accurately obtain the theoretical speed value of the closing speed measuring instrument 10 after dropping. An electromagnetic chuck 5 is provided on the crossbeam 7. The closing speed measuring instrument 10 is movably connected to a connecting steel ball 8. Here, the movable connection is similar to that of a universal wheel connected by a ball, enabling the universal wheel to move relative to the support leg. The connecting steel ball 8 is used to be magnetically attracted by the electromagnetic chuck 5, so that the closing speed measuring instrument 10 is hung on the crossbeam 7. The counterweight container 9 is a counterweight box, and steel balls or inelastic objects can be placed in the counterweight box to achieve counterweight.

[0047] In some embodiments, a driving motor 3 is installed on the mainframe. The driving motor 3 is connected to a lead screw assembly. The driving motor 3 drives the lead screw assembly so that the slider of the lead screw assembly moves in the vertical direction. A rotating motor 2 is provided on the slider of the lead screw assembly. The rotating motor 2 moves in the vertical direction along with the slider of the lead screw assembly. The output shaft of the rotating motor 2 is horizontally arranged. The crossbeam 7 is connected to the output shaft of the rotating motor 2 to rotate along with the output shaft of the rotating motor 2, that is, to swing upwards or downwards. Therefore, the crossbeam can move in the vertical direction and swing in the vertical direction relative to the output shaft of the rotating motor, which is convenient for adjusting the crossbeam 7 to be in a horizontal state. The distance from the rotation axis of the rotating motor 2 in this embodiment to the center of the electromagnetic chuck 5 is 100 mm, which avoids interfering with the volume of the closing speed measuring instrument 10 and if the distance is too far, the crossbeam 7 is prone to tilt, resulting in affecting the determination of the speed of the closing speed measuring instrument 10. Both the driving motor 3 and the rotating motor 2 are connected to the controller 4 through wires. The controller 4 controls the opening and closing of the driving motor 3 and the rotating motor 2 to realize controlling the height position where the crossbeam 7 is located, so that the theoretical speed of the closing speed measuring instrument 10 dropping can be calculated through the calculation formula of free fall motion.

[0048] In some embodiments, the calibration device further includes an inclination sensor 6 which is disposed on the cross beam 7 to detect whether the cross beam 7 is horizontal. The indication error is ≤ ±0.005°, and it is the absolute zero point during use. The controller 4 receives the inclination information of the cross beam 7 detected by the inclination sensor 6, and thus the controller 4 controls the rotation motor 2 and the drive motor 3 to adjust the height of the cross beam 7 according to the information.

[0049] In some embodiments, a leveling mechanism is provided on the main body to keep the dropping area horizontal; the leveling mechanism includes an X-axis electronic level 3-1, a Y-axis electronic level (not shown in the figure), and a leveling adjustment nut 3-2. The X-axis electronic level 3-1 and the Y-axis electronic level are both disposed on the main body, and the leveling adjustment nut 3-2 is disposed at the bottom of the main body. The state of the main body is detected by the X-axis electronic level 3-1 and the Y-axis electronic level (not shown in the figure), and thus the leveling adjustment nut 3-2 is used for leveling.

[0050] In some embodiments, the calibration device further includes a vacuum cup 11 which is used to connect the closing speed measuring instrument 10 to be calibrated; a dropping floor 12 is provided on the main body, and the dropping floor 12 cooperates with the vacuum cup 11 to protect the closing speed measuring instrument 10 to be calibrated. The vacuum cup 11 is located below the closing speed measuring instrument 10 with the cup mouth facing downwards. By using the principle of atmospheric pressure difference generated during the bottom-touching process, it can be adsorbed on the dropping floor 12 to prevent damage to the appearance of the closing speed measuring instrument 10. The dropping floor 12 is made of an inelastic and smooth-surfaced wooden board, so that the sample can freely fall and the vacuum cup 11 can be adsorbed, and it can also prevent damage to the appearance of the closing speed measuring instrument 10.

[0051] The calibration process of using a calibration device for a closing speed measuring instrument 10:

[0052] (1) Preparation work before calibration: Turn on the calibration device, adjust the leveling adjustment nut 3-2 to ensure that the indicating bubbles of the X-axis electronic level 3-1 and the Y-axis electronic level are at the center of the circle, and pre-run (including the movement of the cross beam 7 in the vertical direction and whether the electromagnetic chuck 5 can be normally controlled).

[0053] (2) Weighing by the suspension method: First, fix the weight box on the closing speed measuring instrument 10, then connect the closing speed measuring instrument 10 to the electromagnetic chuck 5, and increase or decrease small steel balls until the surface of the sample vacuum cup 11 is parallel to the dropping floor 12.

[0054] (3) Zero setting: Move the cross beam 7 downward until the vacuum cup 11 just fits the dropping floor 12, and set all parameters of the controller 4 to zero.

[0055] (4) Set the speed: Set the speed calibration point through the controller 4 The cross beam 7 reaches the preset height h.

[0056] (5) Free fall: Start the calibration device, let the door closing speed measuring instrument 10 free fall, and the door closing speed measuring instrument 10 adsorbs on the surface of the falling floor 12.

[0057] Calculation of error:

[0058] Measure each calibration point three times and take the average value. Calculate the indication error of each calibration point according to the following formula:

[0059]

[0060] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. Calibration method for door closing speed measuring instrument, characterized in that, the calibration method comprises the following steps: S1: Hang the door closing speed measuring instrument at a preset height; S2: Detect whether the door closing speed measuring instrument reaches the preset height. If it does not reach the preset height, adjust the door closing speed measuring instrument until it reaches the preset height; S3: Weigh the door closing speed measuring instrument so that the center of gravity of the door closing speed measuring instrument is on the central axis of its handle; S4: Let the door closing speed measuring instrument perform a free fall motion, and record the speed value v when the door closing speed measuring instrument reaches the falling position; S5: Repeat steps S1 - S4 for i times to obtain the velocity values v of the i closing speed measuring instruments when they reach the dropping position, and calculate the average velocity value of the i closing speed measuring instruments when they reach the dropping position According to the free - fall velocity calculation formula Obtain the theoretical velocity v of the closing speed measuring instrument when it reaches the dropping position t , according to the formula: Calculate the indication error δv of the closing speed measuring instrument at the preset height i , where g is the acceleration due to gravity and h is the preset height.

2. The calibration method for door closing speed measuring instrument according to claim 1, characterized in that: In step S1, the door closing speed measuring instrument is adsorbed and hung at the preset height through an electromagnetic adsorption component.

3. The calibration method for door closing speed measuring instrument according to claim 1, characterized in that: In step S2, a grating ruler is used to detect whether the door closing speed measuring instrument reaches the preset height.

4. The calibration method for door closing speed measuring instrument according to claim 3, characterized in that: In step S2, an inclination sensor is also used to detect whether the door closing speed measuring instrument is in a horizontal state.

5. The calibration method for door closing speed measuring instrument according to claim 1, characterized in that: In step S3, the weighing method is: Connect a weighing container to the door closing speed measuring instrument, and add or subtract steel balls in the weighing container to weigh the door closing speed measuring instrument.

6. Calibration device for door closing speed measuring instrument, characterized in that: It includes a grating ruler, a host, a controller, a weighing container and a cross beam. The grating ruler is vertically arranged on the host to detect the height of the cross beam. The cross beam can move vertically relative to the grating ruler. The cross beam is used to hang the door closing speed measuring instrument to be calibrated. The weighing container is used to connect with the door closing speed measuring instrument to be calibrated so that the center of gravity is on the central axis of its handle; There is a falling area of the door closing speed measuring instrument on the host, and the controller is used to control the vertical movement of the cross beam.

7. The calibration device for door closing speed measuring instrument according to claim 6, characterized in that: A driving motor is installed on the host, and the driving motor is connected with a lead screw assembly. The driving motor drives the lead screw assembly so that the slider of the lead screw assembly moves vertically. A rotating motor is arranged on the slider of the lead screw assembly. The rotating motor moves vertically along with the slider of the lead screw assembly. The output shaft of the rotating motor is horizontally arranged, and the cross beam is connected with the output shaft of the rotating motor to rotate along with the output shaft of the rotating motor.

8. The calibration device for door closing speed measuring instrument according to claim 6, characterized in that: It further includes an inclination sensor, and the inclination sensor is arranged on the cross beam to detect whether the cross beam is horizontal.

9. The calibration device for door closing speed measuring instrument according to claim 6, characterized in that: A leveling mechanism is arranged on the host to keep the falling area horizontal; The leveling mechanism includes an X-axis electronic level, a Y-axis electronic level and a horizontal adjusting nut. The X-axis electronic level and the Y-axis electronic level are both arranged on the host, and the horizontal adjusting nut is arranged at the bottom of the host.

10. The calibration device for door closing speed measuring instrument according to claim 6, characterized in that: It also includes a vacuum cup which is used to connect the closing speed measuring instrument to be calibrated; a drop floor is provided on the main body, and the drop floor cooperates with the vacuum cup to protect the closing speed measuring instrument to be calibrated.

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