Computerized steel tape measure indication error detection device and detection method

Abstract

A computerized steel tape measure indication error detection device and detection method are disclosed. A steel tape measure fixture and an electric rotary table assembly are fixedly mounted on the same horizontal line on the front panel of the device housing. The electric rotary table assembly includes an electric rotary table and a scroll wheel mechanism. The scroll wheel mechanism's rotating shaft extends outside the housing's front panel, has an axis slot defined at one end, and is fixedly connected to the electric rotary table at the other end. The housing has an operation panel and a display screen at the top. The housing is internally provided with electrical components, including a controller, a lower computer, and an upper computer. A camera assembly and a grating scale are also fixedly connected to the front of the housing's front panel. The hook of the steel tape measure under inspection is inserted into the axis slot of the electric rotary table assembly. The rotation of the electric rotary table pulls the steel tape measure horizontally, and the camera image and the indication error calculated by the upper computer are displayed in real time on the display screen. The steel tape measure automatic detection device of the present invention utilizes a direct measurement method, occupies a small space, and has the characteristics of rapid, accurate, and automatic detection.

Description

Technical Field

[0001] The invention belongs to the technical field of steel tape measure indication error calibration, and specifically refers to a computerized steel tape measure indication error detection device and detection method. Background Art

[0002] As a basic measuring tool in industrial manufacturing, construction and other fields, the accuracy of steel tape measures directly affects product quality and engineering reliability.

[0003] According to the JJG 4-2015 Steel Tape Verification Procedure, the existing steel tape inspection method mainly uses comparative measurements using standard steel tapes. However, during production and use, steel tapes are prone to measurement deviations due to material deformation, scale marking errors, and environmental factors. The cumulative error is particularly significant for large-sized steel tapes (over 5m).

[0004] Current mainstream calibration technology for steel tape measure indication errors still faces the following technical bottlenecks: First, the calibration device lacks adaptability. Traditional calibration devices often use a 5-meter-long calibration table, which requires a large laboratory space. Furthermore, the standard ruler and the measured ruler must be placed side by side and manually aligned with weights. This makes it difficult to adapt to steel tape measures of varying sizes (e.g., from 0-30,000 mm to 0-100,000 mm), forcing segmented measurement. Furthermore, the insufficient rigidity of the support structure can easily cause the tape to bend or deflect, affecting calibration accuracy. Although some improved devices utilize support slides and zero adjustment components to adjust the length, they still rely on manual operation, resulting in low efficiency. Second, manual operation introduces errors. The current calibration process requires visual comparison of the scales of the standard ruler and the measured ruler, with point-by-point error recording. For example, conventional methods require aligning the zero point of the master ruler with the measured ruler before manually moving the reading microscope for measurement at multiple comparison points (e.g., 1-meter, 2-meter, and 5-meter intervals). This repetitive operation can easily lead to visual fatigue and positioning deviations, resulting in cumulative errors of ±1.5 mm (according to domestic standards) or even higher. In addition, tension control relies on manually hanging a heavy hammer. If the standard tension (such as 49N) is not followed, additional errors will be generated due to elastic deformation. -5 1000 metric tons (1000 metric tons / °C) is temperature-sensitive, but most calibration environments lack temperature control and rely solely on room temperature (20°C ± 8°C). This results in ineffective compensation for temperature drift errors. Furthermore, insufficient leveling of the tape measure or an uneven support surface can introduce geometric errors. For example, a 0.4m height difference between the ends of a 30m tape measure can result in an error of 2.6mm. Fourth, the tape measure strip is made of stainless steel, posing a risk of hand-cutting during manual operation.

[0005] Chinese invention patent CN117928331B discloses a calibration device for a steel tape measure used for measurement, comprising a test platform, a steel tape measure body placed on the test platform surface, a tape measure strip housed within the steel tape measure body, a positioning mechanism provided on the test platform surface that cooperates with the steel tape measure body, the positioning mechanism comprising a clamping assembly and an extension assembly, and a protective mechanism provided on the test platform surface that cooperates with the tape measure strip, the protective mechanism comprising a squeeze column, a support assembly, and a pressing assembly. This invention provides auxiliary squeezing and positioning functions. By providing a support assembly and a pressing assembly that cooperate with each other, the position of the squeeze column can be automatically adjusted as the tape measure strip extends and retracts within the steel tape measure body, thereby protecting the tape measure from squeezing, effectively improving the stability of the tape measure during testing and resolving the issue with existing calibration devices where the tape measure strip easily falls off and automatically rewinds into the steel tape measure body, posing a risk of cutting the palm. However, the existing JJG 4-2015 steel tape measure calibration method is still used, requiring a large space for the test platform, and no intelligent measurement solution is provided for steel tape measurement.

[0006] Chinese invention patent CN116972709B discloses a method and system for analyzing the error of steel tape measurement calibration. The method has the technical effects of high degree of automation, precise calibration and high calibration efficiency to a certain extent. It provides two embodiments. The overall idea is: zero point correction of the steel tape measurement calibration device; when the steel tape measurement reaches a predetermined position, the clamping unit grabs the steel tape measurement and cooperates with the measuring block and fixes the measuring block and the measuring end of the steel tape measurement by the pressing block. At this time, the steel tape measurement is fixed by the clamping unit; the sliding of the measuring block is controlled, and the sliding distance of the measuring block is recorded, and the sliding distance is used as the standard distance; the image of the zero point line and the scale line of the steel tape measurement is performed by the CCD sensor to establish a verification image set; the processing network is configured according to the acquisition parameters of the CCD sensor, and the recognition processing of the verification image set is performed by the processing network to generate a scale recognition result; error analysis is performed based on the standard distance and the scale recognition result to generate an error calibration result. The document states that the relative sliding distance of the measuring block is used as the standard displacement, and CCD is used to capture images to calculate the error of the steel tape. When the steel tape reaches the position, the clamping unit activates and secures the steel tape to ensure that it does not move or shake during the measurement process. Therefore, this solution, which uses sliding as the standard distance, requires a large motion platform and a large space for the calibration table, at least 5m to meet the testing requirements of most steel tapes. Furthermore, it does not explain how to test long-range steel tapes, such as 50m, and cannot achieve automatic testing of long-range steel tapes.

[0007] Chinese invention patent CN116164608B discloses a semi-automated, efficient steel tape measure calibration device. The device comprises a calibration platform, a positioning block disposed on the calibration platform, and a clamping device configured as a fixture. A fixture is also provided on one side of the clamping device on the calibration platform, and a measuring structure is provided on the other end of the fixture. The measuring structure is used to measure the steel tape measure. A limiter is provided on the other side of the measuring structure on the calibration platform. This device positions the steel tape measure between the positioning blocks. When a soft capsule is squeezed, a first slider within the guide block is squeezed out, thereby driving the limiter connected to the first slider to move, thereby achieving zero positioning. At this point, the limiter slot continues to advance, automatically recording the error value. By fixing the measured distance, section calibration is achieved, thereby increasing the calibration efficiency of the steel tape measure to a certain extent. However, this solution also uses a standard ruler for manual comparison measurement, requiring a large space on the calibration platform and resulting in a low degree of automation.

[0008] Similarly, the solutions disclosed in Chinese utility model patents CN222718812U, CN222579103U, CN221781396U, CN221484376U, CN221425521U, etc. all use a large horizontal calibration platform to calibrate the steel tape, and the calibration platform occupies a large space.

[0009] Therefore, it is urgent to develop an automatic detection device for steel tape measure indication error that occupies a small space and adopts a direct measurement method to achieve fast, accurate and automatic detection of steel tape measure. Summary of the Invention

[0010] One of the technical problems to be solved by the present invention is to provide a computer-based device for detecting the indication error of a steel tape measure, which occupies a small space and is fast, accurate, efficient and has high efficiency.

[0011] The second technical problem to be solved by the present invention is to provide a fast, accurate, efficient, computerized method for detecting the error in the indication of a steel tape measure.

[0012] The present invention is achieved in that:

[0013] One of the technical solutions:

[0014] A computerized steel tape measure indication error detection device comprises: a housing, a steel tape measure clamp and an electric rotating platform assembly fixedly mounted on the same horizontal line of a front panel of the housing; the electric rotating platform assembly comprises: an electric rotating platform and a rolling wheel mechanism connected thereto;

[0015] The electric rotating platform is installed inside the housing, and the rotating shaft of the scroll wheel mechanism extends out of the front plate of the housing, with an end thereof being provided with an axis slot and the other end being fixedly connected to the electric rotating platform;

[0016] The top of the housing is provided with an operation panel, and the operation panel is provided with a display screen;

[0017] An electrical component is provided inside the housing, and the electrical component includes: a controller and a lower computer;

[0018] A sheet metal mounting base is also fixedly connected to the front of the front plate of the housing, and a single-axis module and a grating ruler are provided on the sheet metal mounting base. The reading head on the grating ruler is fixedly connected to the side of the single-axis module through a mounting plate; a camera assembly is also fixedly connected above the single-axis module; the grating ruler accurately reads the position information of the single-axis module in real time and transmits it to the lower computer;

[0019] The camera assembly includes: a support, a column, a connecting seat, a connecting plate, a camera, a fixing bracket, and an LED lamp; the support is fixedly connected to the top of the single-axis module, and the column is fixedly connected to the top of the support; the camera is fixedly connected to the connecting seat on the column via the connecting plate, and the LED lamp is further provided below the camera, and the side of the LED lamp is connected to the connecting seat via the fixing bracket. The camera is located above the inspected steel tape measure, captures images of the scale body of the inspected steel tape measure, and uploads them to the lower computer;

[0020] The single-axis module, the grating ruler and the electric rotary table are all connected to the controller;

[0021] The steel tape measure to be inspected is fixedly installed on the steel tape measure clamp, and the hook of the steel tape measure to be inspected is inserted into the shaft groove of the electric rotary table assembly. The steel tape measure is pulled horizontally by the rotation of the electric rotary table, and the display screen on the operation panel of the casing displays the image captured by the camera and the error result of the steel tape measure indication in real time.

[0022] Furthermore, two rolling wheel assemblies are provided between the steel tape clamp and the electric rotating table assembly and are installed in the housing;

[0023] The two rolling wheel lifting assemblies are symmetrically arranged;

[0024] Each of the rolling wheel lifting assemblies has two rollers, which are respectively arranged above and below the inspected steel tape measure, to realize the rotational movement and lifting and pressing action of the two rollers, so as to stabilize and flatten the inspected steel tape measure.

[0025] Furthermore, each of the rolling wheel lifting assemblies includes: a motor, a transmission mechanism, a first rotating wheel, a second rotating wheel, a first transmission shaft, a second transmission shaft, a third transmission shaft, a gear box, and the two rollers;

[0026] The driving shaft wheel of the motor drives the first rotating wheel and the second rotating wheel to rotate in the same direction through the transmission mechanism;

[0027] One end of the first transmission shaft is connected to the center of the first rotating wheel, and the other end is connected to the lower roller of the two rollers;

[0028] One end of the second transmission shaft is connected to the center of the second rotating wheel, and the other end passes through the gear box and extends out of the gear box; a gear transmission mechanism is provided in the gear box, and inside the gear box, the second transmission shaft drives the third transmission shaft to rotate in the opposite direction through the gear transmission mechanism, and one end of the third transmission shaft extends out of the gear box and connects to the upper roller of the two rollers;

[0029] A wheel lifting mechanism is fixedly installed above the gear box, and the wheel lifting mechanism includes: a lifting top plate, a lifting pressure plate and a knob shaft;

[0030] The top lifting plate is installed on the gear box in a sloped manner, the top of the top lifting plate abuts the top of the "7"-shaped lifting and pressure plate, the middle of the lifting and pressure plate is fixedly connected to the extended end of the knob shaft, and the bottom of the lifting and pressure plate abuts the middle of the top lifting plate; turning the knob on the knob shaft rotates the lifting and pressure plate, and then pushes the top lifting plate, thereby lifting or lowering the upper roller.

[0031] Furthermore, the top lifting plate in each of the wheel lifting mechanisms is also in contact with a fine-tuning component;

[0032] The two fine-tuning components are symmetrically arranged;

[0033] Each of the fine-tuning components includes: a rotary rod, a knurled wheel, a threaded support, a hand wheel, and a light support;

[0034] One end of the rotating rod is fixedly connected to the straight knurled wheel; the threaded support, the hand wheel and the optical support are sequentially arranged on the rotating rod;

[0035] The threaded support and the side edges of the optical support are fixedly mounted on the front panel of the housing;

[0036] A spring plate is provided on the top of the optical support, and a steel ball is provided between the spring plate and the straight knurled wheel;

[0037] The other end of the rotating rod is in contact with the top lifting plate, and the rotating rod is pressed against the top lifting plate by rotating the hand wheel to fine-tune the distance between the two rollers.

[0038] Furthermore, the steel tape measure clamp includes: an L-shaped fixing bracket, two cylindrical seats, and a U-shaped support rod; the vertical end of the L-shaped fixing bracket is fixed to the front panel of the casing, and the two cylindrical seats are located at the horizontal end of the L-shaped fixing bracket close to the vertical end; the two ends of the U-shaped support rod are bent downward and extend into the two cylindrical seats and are fixedly connected by springs.

[0039] Technical solution 2:

[0040] A computerized steel tape measure indication error detection method, using the computerized steel tape measure indication error detection device as described above, comprises the following steps:

[0041] Step 1: Install the steel tape to be inspected on the steel tape fixture;

[0042] Step 2: Pull out the hook of the steel tape to be inspected and insert the hook into the shaft slot of the electric rotary table assembly;

[0043] Step 3: Manually operate the operation panel to move the camera to the top of the scale line of the inspected steel tape by moving the single-axis module, stop at the "inspection position", adjust the up and down and rotation position of the connecting base to make the camera image clear, and lock the connecting base;

[0044] Then, manually operate the operation panel to move the camera to the "zero position" by moving the single-axis module, operate the "starting scale line" button on the operation panel so that the starting scale line coincides with the left side of the shaft groove of the rotating shaft, and the grating scale connected to the camera is cleared to zero, and the electric rotating stage is cleared to zero at the same time;

[0045] Step 4: Move the camera to the "detection position" and move it along the inspected steel tape from the "zero point" to the "detection position" and stop. At this time, the reading displayed on the screen is Lg, which represents the fixed distance value between the "zero point" and the "detection position";

[0046] Step 5: Start the test at the first target detection point at the 1000mm mark:

[0047] Calculate the horizontal target distance Lx'1 that the electric rotary table needs to rotate from the "zero position" to the "test position" of the first target detection point of the inspected steel tape. Lx'1 = Lb1 - Lg, where Lb1 is the nominal value of the first target detection point, i.e., 1000mm. After the calculation is completed, the motor of the electric rotary table is rotated through closed-loop control to reach the horizontal target distance Lx'1. At this time, the actual horizontal distance rotated is Lx1. The actual distance displayed on the standard scale line Ls on the display screen is Ls = Lg + Lx1.

[0048] Step 6: Move the left and right scale lines on the operation panel so that the left and right scale lines coincide with the left and right edges of the scale line of the first target measurement point of the inspected steel tape measure, thereby generating a middle scale line Lm of the first target measurement point of the inspected steel tape measure. Utilize the distance measurement function of the camera's same field of view to measure the distance between Lm and the standard scale line Ls as L1. The sign of L1 is defined as "+" when the middle scale line Lm is to the left of Ls and "-" when Lm is to the right of Ls.

[0049] Step 7: Calculate the indication error △L1 of the first target detection point of the inspected steel tape:

[0050] △L1=L1+ Lg+Lx1-Lb1

[0051] Step 7: Start the test at the second target detection point at the 2000mm mark:

[0052] The second target detection point of the inspected steel tape is Lb2 = 2000mm. When the electric rotary table reaches the "detection position", the horizontal target distance it needs to rotate is Lx'2, which is 1000mm. At this time, the motor of the electric rotary table reaches the target horizontal distance Lx'2 = 1000mm through closed-loop control. At this time, the actual horizontal distance rotated is Lx2. The actual distance of the standard scale line Ls displayed on the screen is Ls = Lg + Lx1 + Lx2. According to step 6, the distance between Lm and the standard scale line Ls is L2. The indication error of the second target detection point is △L2:

[0053] △L2= L2+ Lg+Lx1+ Lx2-Lb2;

[0054] Similarly, according to the JJG 4-2015 steel tape measurement calibration requirements, complete the remaining test points meter by meter, and calculate the indication error according to the formula in step seven. After the test is completed, the electric rotary table reverses to the origin.

[0055] The advantages of the present invention are:

[0056] 1. The computerized structure makes the whole detection device highly compact, compact and flexible, and the detection device occupies a small laboratory space;

[0057] 2. Direct measurement is achieved through camera technology, which changes the traditional steel tape comparison method and reduces the error introduced by tensile deformation during the traditional steel tape measurement process;

[0058] 3. Two pairs of upper and lower rollers with adjustable gaps are used to protect the inspected steel tape, pressing the inspected steel coil. This facilitates camera data recognition and reduces the error introduced by the curling deformation of the inspected steel tape itself, thereby improving detection accuracy. At the same time, the two pairs of rollers can realize the up and down lifting function to facilitate the loading and unloading of the inspected steel tape.

[0059] 4. The electric rotating table drives the winding wheel mechanism to rotate, realizing the retraction and release of the inspected steel coil, providing the initial zero position of the inspected steel tape, and also retracting the inspected tape to further protect the steel tape from being cut by the palm.

[0060] 5. The left and right movement of the single-axis module is used to realize the recognition of the camera zero position and the detection of the indication error, which improves the utilization efficiency of a single camera and makes the structure more compact;

[0061] 6. Use exclusive steel tape measure fixture to achieve quick loading and unloading of the inspected steel tape measure;

[0062] 7. The measurement software can automatically process data and generate original test records, thus realizing paperless and intelligent steel tape test. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0064] Figure 1 It is a schematic diagram of the appearance structure of the detection device of the present invention in use state.

[0065] Figure 2 It is a front perspective view of the front panel of the housing in the detection device of the present invention (without the steel tape clamp).

[0066] Figure 3 It is a schematic diagram of the back of the housing front plate in the detection device of the present invention.

[0067] Figure 4 It is a structural schematic diagram of the first rolling wheel lifting assembly in the detection device of the present invention.

[0068] Figure 5 It is a structural schematic diagram of the second rolling wheel lifting assembly in the detection device of the present invention.

[0069] Figure 6 It is a schematic structural diagram of the first fine-tuning component in the detection device of the present invention.

[0070] Figure 7 It is a schematic structural diagram of the second fine-tuning component in the detection device of the present invention.

[0071] Figure 8 It is a structural schematic diagram of the scroll wheel mechanism in the detection device of the present invention.

[0072] Figure 9 It is a schematic structural diagram of the steel tape measure clamp in the detection device of the present invention.

[0073] Figure 10 It is a schematic diagram of the positional relationship among the single-axis module, grating ruler and mounting seat in the detection device of the present invention.

[0074] Figure 11 It is a structural schematic diagram of the camera assembly in the detection device of the present invention.

[0075] Figure 12 It is a schematic diagram of the operation panel and display screen in the detection device of the present invention.

[0076] Figure 13 It is a schematic diagram of picking up the zero-point image of the steel tape measure in the detection device of the present invention.

[0077] Figure 14 It is a schematic diagram of picking up the image of the steel tape measure engraved lines on the display screen of the detection device of the present invention.

[0078] Figure 15 It is a block diagram of the system control principle in the detection device of the present invention.

[0079] Figure 16 It is a schematic diagram of the software execution flow of the present invention. DETAILED DESCRIPTION

[0080] See also Figures 1 to 16 As shown, a computerized steel tape measure indication error detection device comprises: a housing 4, a steel tape measure clamp 11 and an electric rotating platform assembly 3 fixedly mounted on the same horizontal line of a front plate 41 of the housing 4;

[0081] The electric turntable assembly 3 includes: an electric turntable 31 (model E-RMPG40) and a scroll wheel mechanism 32 connected to it; the electric turntable 31 is mounted on the rear vertical plate 42 inside the housing 4, and the rotating shaft 321 of the scroll wheel mechanism 32 extends out of the front plate 41 of the housing 4. Its end is defined by an axis groove 3211, and the other end is fixedly connected to the electric turntable 31; the scroll wheel mechanism 32 includes the rotating shaft 321 and a bearing 322 for easy installation and fixation, a flange 323, and a limiting shaft 324 for limiting the bearing 322.

[0082] The top of the housing 4 is provided with an operation panel 7, on which a display screen 71 is provided;

[0083] The housing 4 is internally provided with electrical components, which include: a controller and a lower computer;

[0084] A sheet metal mounting base 81 is also fixedly connected to the front of the front plate 41 of the housing 4. A single-axis module 82 and a grating ruler 86 are provided on the sheet metal mounting base 81. A reading head 85 on the grating ruler 86 is fixedly connected to the side of the single-axis module 82 via a mounting plate 84. A camera assembly 9 is also fixedly connected above the single-axis module 82 via a rotating mounting plate 83. The scale on the grating ruler 86 accurately reads the position information of the single-axis module 82 in real time and transmits it to the lower computer.

[0085] The camera assembly 9 includes a support 91, a column 92, a connecting base 93, a camera 94, a connecting plate 95, an LED light 96, and a fixing bracket 97. The support 91 is fixedly connected to the top of the single-axis module 82, the column 92 is fixedly connected to the top of the support 91, and the camera 94 is fixedly connected to the connecting base 93 on the column 92 via a connecting plate 95. An LED light 96 is also provided below the camera 94. The side of the LED light 96 is connected to the connecting base 93 via a fixing bracket 97. The camera 94 is located above the inspected steel tape measure 1 and captures images of the scale body of the inspected steel tape measure 1 and uploads them to the lower computer.

[0086] The single-axis module 82, the grating ruler 86 and the electric rotary table 31 are all connected to the controller;

[0087] The inspected steel tape measure 1 is fixedly installed on the steel tape measure clamp 11, and the hook of the inspected steel tape measure 1 is inserted into the shaft groove 3211 of the electric rotary table assembly 3. The inspected steel tape measure 1 is pulled horizontally by the rotation of the electric rotary table 31, and the display screen 71 on the operation panel 7 of the casing 4 displays the image captured by the camera 94 and the error result of the steel tape measure indication in real time.

[0088] Four feet 12 are provided below the housing 4 , and another foot 13 is provided below the sheet metal mounting base 81 .

[0089] Two rolling wheel assemblies (a first rolling wheel assemblies 51 and a second rolling wheel assemblies 52 ) are spaced apart between the steel tape clamp 11 and the electric rotating table assembly 3 and are installed in the housing 4 ;

[0090] The first rolling wheel lifting assembly 51 and the second rolling wheel lifting assembly 52 are symmetrically arranged and have the same structure;

[0091] The first rolling wheel lifting assembly 51 has upper and lower rollers 5101 and 5102, and the second rolling wheel lifting assembly 52 has upper and lower rollers 5201 and 5202, which are respectively arranged at the upper and lower parts of the steel tape measure 1, to realize the rotational movement and lifting and pressing action of the rollers 5101, 5102, 5201, and 5202, so as to stabilize and flatten the steel tape measure 1.

[0092] The following takes the first rolling wheel lifting assembly 51 as an example to illustrate its specific structure, including: a motor 5103, a transmission mechanism 5104 (belt drive or gear drive, a pulley is used in this embodiment, and gear drive can also be used in actual practice), a first rotating wheel 5105, a second rotating wheel 5106, a first transmission shaft 5107, a second transmission shaft 5108, a third transmission shaft 5109, a gear box 5110, and two rollers 5101 and 5102.

[0093] The motor 5103 is mounted on the rear vertical plate 42 inside the housing 4 via two support columns 51031. The drive shaft 51032 of the motor 5103 drives the first rotating wheel 5105 and the second rotating wheel 5106 to rotate in the same direction through the transmission mechanism 5104;

[0094] One end of the first transmission shaft 5107 is connected to the center of the first rotating wheel 5105, and the other end is connected to the lower roller 5102 of the two rollers;

[0095] One end of the second transmission shaft 5108 is connected to the center of the second rotating wheel 5106 , and the other end passes through the gear box 5110 and extends out of the gear box 5110 ;

[0096] A gear transmission mechanism is provided within the gear box 5110. Within the gear box 5110, the second transmission shaft 5108 drives the third transmission shaft 5109 to rotate in the opposite direction through the gear transmission mechanism. One end of the third transmission shaft 5109 extends outside the gear box 5110 and connects to the upper roller 5101 of the two rollers.

[0097] A wheel-lifting mechanism is fixedly installed above the gearbox 5110. The wheel-lifting mechanism includes: a top-lifting plate 5111, a lifting and pressing plate 5112, and a knob shaft 5113. The top-lifting plate 5111 is installed on the gearbox 5110 in a sloped manner. The top of the top-lifting plate 5111 abuts against the top of the "7"-shaped lifting and pressing plate 5112. The middle of the lifting and pressing plate 5112 is fixedly connected to the extended end of the knob shaft 5113, and the bottom of the lifting and pressing plate 5112 abuts against the middle of the top-lifting plate 5111. Turning the knob 5114 on the knob shaft 5113 rotates the lifting and pressing plate 5112, which in turn pushes the top-lifting plate 5111, thereby raising or lowering the upper roller 5101. The top-lifting plate 5111 in the wheel-lifting mechanism also abuts against a first fine-tuning component 61.

[0098] The first fine-tuning component 61 and the second fine-tuning component 62 are symmetrically arranged and have the same structure;

[0099] The following describes the specific structure of the first fine-tuning assembly 61 as an example. The first fine-tuning assembly 61 includes: a rotating rod 611, a straight knurled wheel 612, a threaded support 613, a handwheel 614, and an optical support 615. One end of the rotating rod 611 is fixedly connected to the straight knurled wheel 612; the threaded support 613, the handwheel 614, and the optical support 615 are sequentially installed on the rotating rod 611; the side edges of the threaded support 613 and the optical support 615 are fixedly mounted on the front panel 41 of the housing 4.

[0100] A spring plate 616 is provided at the top of the optical support 615, and a steel ball 617 is provided between the spring plate 616 and the straight knurled wheel 612; the other end of the rotating rod 611 is in contact with the top lifting plate 5111, and by rotating the hand wheel 614, the rotating rod 611 is pressed against the top lifting plate 5111 to fine-tune the distance between the two rollers 5101 and 5102.

[0101] The steel tape measure clamp 11 comprises an L-shaped fixing bracket 111, two cylindrical seats 112, and a U-shaped support rod 113. The vertical end of the L-shaped fixing bracket 111 is fixed to the front panel 41 of the housing 4, and the two cylindrical seats 112 are located at the horizontal end of the L-shaped fixing bracket 111 near the vertical end. The two ends of the U-shaped support rod 113 are bent downward and extend into the two cylindrical seats 112, which are fixed together via springs. To secure the steel tape measure 1, the U-shaped support rod 113 is pulled upward a distance, the steel tape measure 1 is placed on the horizontal end of the L-shaped fixing bracket 111, and the U-shaped support rod 113 is released. Under the restoring force of the spring, the U-shaped support rod 113 firmly clamps the top of the steel tape measure 1.

[0102] The electric rotating platform 31, the first rolling wheel assembly 51, the second rolling wheel assembly 52 and the single-axis module 82 are all driven by a designed control system (the system control principle block diagram is shown in FIG. Figure 15 As shown in the figure), it can be realized by accurately positioning each target detection point. The detection process is designed by software (see the software execution flow chart for details). Figure 16 ) is realized by operating the control on the operation panel 7 to start the driving of the electric rotating table 31 and the first rolling wheel lifting assembly 51 and the second rolling wheel lifting assembly 52 and to perform the detection process.

[0103] The specific detection method includes the following steps:

[0104] Step 1: Install the steel tape measure 1 to be inspected on the steel tape measure fixture 11;

[0105] Step 2: Pull out the hook of the inspected steel tape 1 and insert it into the shaft groove 3211 of the electric rotary table assembly 3;

[0106] Step 3: Manually operate the operation panel 7 to move the camera 94 to the position above the scale line of the inspected steel tape 1 by moving the single-axis module 82, stop at the "inspection position", adjust the up and down and rotation positions of the connecting base 93 so that the image of the camera 94 is clear, and lock the connecting base 93;

[0107] Then, manually operate the operation panel 7 to move the camera 94 to the "zero position" by moving the single-axis module 82. Press the "Start Marking Line" button on the display screen 71 so that the starting marking line L0 coincides with the left side of the shaft groove 3211 of the rotating shaft. The grating scale 86 connected to the camera 94 is reset to zero, and the electric rotating stage 31 is reset to zero at the same time.

[0108] Step 4: Move the camera to the "detection position". The camera 94 moves along the inspected steel tape 1 from the "zero point" to the "detection position" and stops. At this time, the reading displayed on the display screen 71 by the grating ruler 86 is Lg, which represents the fixed distance value between the "zero point" and the "detection position".

[0109] Step 5: Start the test at the first target detection point at the 1000mm mark:

[0110] Calculate the horizontal target distance Lx'1 that the electric rotary table 31 needs to rotate when the first target detection point of the inspected steel tape 1 moves from the "zero position" to the "detection position". Lx'1 = Lb1 - Lg, where Lb1 is the nominal value of the first target detection point, i.e., 1000 mm. (Assuming the Lg reading is 250.002 mm, then Lx'1 = Lb1 - Lg = 1000 - 250.002 = 749.998 mm.) After the calculation is completed, the motor of the electric rotary table 31 is rotated through closed-loop control to reach the horizontal target distance Lx'1. At this time, the actual horizontal distance rotated is Lx1. The actual distance of the standard scale line Ls displayed on the display screen 71 is Ls = Lg + Lx1.

[0111] Step 6: Move the left and right scale lines on the display screen 71 so that the left scale line L2 and the right scale line L1 coincide with the left and right edges of the scale line of the first target measuring point of the actual inspected steel tape 1, respectively, to generate a middle scale line Lm of the first target measuring point of the inspected steel tape. Utilize the distance measurement function of the camera's same field of view to measure the distance between Lm and the standard scale line Ls as L1. The sign of L1 is defined as "+" when the middle scale line Lm is to the left of Ls and "-" when Lm is to the right of Ls.

[0112] Step 7: Calculate the indication error △L1 of the first target detection point of the inspected steel tape 1:

[0113] △L1=L1+ Lg+Lx1-Lb1

[0114] Step 7: Start the test at the second target detection point at the 2000mm mark:

[0115] The second target detection point of the inspected steel tape 1 is Lb2=2000mm. When the electric rotary table reaches the "detection position" position, the horizontal target distance it needs to rotate is Lx'2, which is 1000mm (the distance between the 1m scale line of the first target detection point and the 2m scale line of the second target detection point). At this time, the motor of the rotating electric rotary table reaches the target horizontal distance Lx'2=1000mm through closed-loop control. At this time, the actual horizontal distance rotated is Lx2. The actual distance of the standard scale line Ls displayed on the display screen 71 is Ls= Lg+Lx1+ Lx2. According to step 6, the distance between Lm and the standard scale line Ls is L2. The indication error of the second target detection point is △L2:

[0116] △L2= L2+ Lg+Lx1+ Lx2-Lb2;

[0117] Similarly, according to the JJG 4-2015 steel tape measurement calibration requirements, complete the remaining test points meter by meter, and calculate the indication error according to the formula in step seven. After the test is completed, the electric rotary table reverses to the origin.

[0118] The operation process is as follows:

[0119] 1. Turn on the power of the detection device, open the automatic measurement software to warm up the device, check the steel tape 1 to be tested and place it in the same room with the device for isothermal treatment. The isothermal treatment time shall be in accordance with the requirements of JJG 4-2015.

[0120] 2. Input the relevant information to be inspected in the automatic measurement software, set the total length of the inspected steel tape 1, and select the "scrolling mode", "video recording mode" and "buzzing sound" compound functions as needed.

[0121] 3. Fix the inspected steel tape measure 1 on the steel tape measure fixture 11, and pull the hook of the inspected steel tape measure 1 to hang it in the shaft groove 3211. Move the camera 94 so that the camera 94 is above the shaft groove 3211. Adjust the position and camera brightness of the camera 94 so that the camera image displayed on the display screen 71 of the operation panel 7 by the camera 94 is clear.

[0122] 4. Press the "Detect" button, move the camera 94 to the "zero point" position, press the "START" button, the motor of the electric rotary table 31 moves to the first target detection point, move the left line alignment and the right line alignment so that the left and right scale lines coincide with the image scale lines of the actual target measurement point of the steel tape measure. Press the SET button to confirm that the automatic measurement software automatically generates the indication error of the first detection point, then press the "START" button to repeat the above measurement until the indication error of all measurement points is measured.

[0123] 5. After the automatic measurement software completes the automatic measurement, press the "Scroll Mode" button once, then press the "START" button. The motor of the electric rotary table 31 will reverse and move to the zero point. Remove the hook of the inspected steel tape 1 and remove the inspected steel tape 1 from the steel tape fixture 11.

[0124] 7. Turn off the power and the test is completed.

[0125] The present invention provides a device and a method for detecting the indication error of a steel tape measure, which are high-precision, computer-based, compact in structure, small in space, easy to operate and efficient, and capable of automatic detection.

[0126] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. A computerized steel tape measure indication error detection device, characterized in that: include: A housing, wherein a steel tape measure fixture and an electric rotating table assembly are fixedly mounted on the same horizontal line of a front plate of the housing; The electric rotating table assembly includes: an electric rotating table and a scroll wheel mechanism connected thereto; The electric rotating platform is installed inside the housing, and the rotating shaft of the scroll wheel mechanism extends out of the front plate of the housing, with an end thereof being provided with an axis slot and the other end being fixedly connected to the electric rotating platform; The top of the housing is provided with an operation panel, and the operation panel is provided with a display screen; An electrical component is provided inside the housing, and the electrical component includes: a controller and a lower computer; A sheet metal mounting base is also fixedly connected to the front of the front plate of the housing, and a single-axis module and a grating ruler are provided on the sheet metal mounting base. The reading head on the grating ruler is fixedly connected to the side of the single-axis module through a mounting plate; a camera assembly is also fixedly connected above the single-axis module; the grating ruler accurately reads the position information of the single-axis module in real time and transmits it to the lower computer; The camera assembly captures the scale of the inspected steel tape and uploads the image to the slave computer; The single-axis module, the grating ruler and the electric rotary table are all connected to the controller; The steel tape measure to be inspected is fixedly mounted on the steel tape measure fixture, and the hook of the steel tape measure to be inspected is inserted into the shaft groove of the electric rotary table assembly. The display screen on the operation panel of the housing displays the image captured by the camera and the error result of the steel tape measure indication in real time; Two rolling wheel assemblies are provided between the steel tape clamp and the electric rotating table assembly and are installed in the housing; The two rolling wheel lifting assemblies are symmetrically arranged; Each of the rolling wheel lifting assemblies includes: a motor, a transmission mechanism, a first rotating wheel, a second rotating wheel, a first transmission shaft, a second transmission shaft, a third transmission shaft, a gear box, and two rollers; The driving shaft wheel of the motor drives the first rotating wheel and the second rotating wheel to rotate in the same direction through the transmission mechanism; One end of the first transmission shaft is connected to the center of the first rotating wheel, and the other end is connected to the lower roller of the two rollers; One end of the second transmission shaft is connected to the center of the second rotating wheel, and the other end passes through the gear box and extends out of the gear box; a gear transmission mechanism is provided in the gear box, and inside the gear box, the second transmission shaft drives the third transmission shaft to rotate in the opposite direction through the gear transmission mechanism, and one end of the third transmission shaft extends out of the gear box and connects to the upper roller of the two rollers; A wheel lifting mechanism is fixedly installed above the gear box, and the wheel lifting mechanism includes: a lifting top plate, a lifting pressure plate and a knob shaft; The top lifting plate is installed on the gear box in a sloped manner, the top of the top lifting plate abuts the top of the "7"-shaped pressure lifting plate, the middle of the pressure lifting plate is fixedly connected to the extended end of the knob shaft, and the bottom of the pressure lifting plate abuts the middle of the top lifting plate; The top lifting plate in each of the wheel lifting mechanisms also abuts against a fine-tuning component; The two fine-tuning components are symmetrically arranged; Each of the fine-tuning components includes: a rotary rod, a knurled wheel, a threaded support, a hand wheel, and a light support; One end of the rotating rod is fixedly connected to the straight knurled wheel; the threaded support, the hand wheel and the optical support are sequentially arranged on the rotating rod; The threaded support and the side edges of the optical support are fixedly mounted on the front panel of the housing; A spring plate is provided on the top of the optical support, and a steel ball is provided between the spring plate and the straight knurled wheel; The other end of the rotary rod is in contact with the top lifting plate, and by rotating the hand wheel, the rotary rod is pressed against the top lifting plate to fine-tune the distance between the two rollers; The two rollers are respectively arranged at the upper and lower parts of the inspected steel tape, so as to realize the rotation movement and lifting and pressing action of the two rollers, and are used to stabilize and flatten the inspected steel tape.

2. A computerized steel tape measure indication error detection device as claimed in claim 1, characterized in that: The camera assembly includes: a support, a column, a connecting seat, a connecting plate, a camera, a fixing bracket and an LED lamp; the support is fixedly connected to the top of the single-axis module, and the column is fixedly connected to the top of the support; the camera is fixedly connected to the connecting seat on the column through the connecting plate, and the LED lamp is also provided under the camera. The side of the LED lamp is connected to the connecting seat through the fixing bracket, and the camera is located above the inspected steel tape measure.

3. A computerized steel tape measure indication error detection device as claimed in claim 1, characterized in that: The steel tape measure clamp includes: an L-shaped fixing bracket, two cylindrical seats, and a U-shaped support rod; the vertical end of the L-shaped fixing bracket is fixed to the front panel of the casing, and the two cylindrical seats are located at the horizontal end of the L-shaped fixing bracket close to the vertical end; the two ends of the U-shaped support rod are bent downward and extend into the two cylindrical seats and are fixedly connected by springs.

4. A computerized method for detecting error in indication of a steel tape measure, characterized in that: Using a computerized steel tape measure indication error detection device as described in any one of claims 1 to 3, the detection method comprises the following steps: Step 1: Install the steel tape to be inspected on the steel tape fixture; Step 2: Pull out the hook of the steel tape to be inspected and insert the hook into the shaft slot of the electric rotary table assembly; Step 3: Manually operate the single-axis module on the operation panel to move the camera to the position above the scale line of the inspected steel tape, stop at the "inspection position", adjust the up and down and rotation position of the connecting base to make the camera image clear, and lock the connecting base; Then, manually operate the camera to the "zero position" by moving the single-axis module on the operation panel, operate the "starting mark" button on the operation panel so that the starting mark coincides with the left side of the shaft groove of the rotating shaft, and the grating ruler connected to the camera is reset to zero, and the electric rotating stage is reset to zero at the same time; Step 4: Move the camera to the "detection position" and move it along the inspected tape from the "zero position" to the "detection position" and stop. At this time, the reading displayed on the screen is Lg, which represents the fixed distance between the "zero position" and the "detection position"; Step 5: Start the test at the first target detection point at the 1000mm mark: Calculate the horizontal target distance Lx'1 that the electric rotary table needs to rotate from the "zero position" to the "test position" of the first target detection point of the inspected steel tape measure. Lx'1 = Lb1 - Lg, where Lb1 is the nominal value of the first target detection point, i.e., 1000mm. After the calculation is completed, the motor of the electric rotary table is rotated through closed-loop control to reach the horizontal target distance Lx'1. At this time, the actual horizontal distance rotated is Lx1. The actual distance displayed on the standard scale line Ls on the display screen is Ls = Lg + Lx1. Step 6: Move the left and right scale lines on the operation panel so that the left and right scale lines coincide with the left and right edges of the scale line of the first target measurement point of the inspected steel tape measure, thereby generating a middle scale line Lm of the first target measurement point of the inspected steel tape measure. Utilize the distance measurement function of the camera's same field of view to measure the distance between Lm and the standard scale line Ls as L1. The sign of L1 is defined as "+" when the middle scale line Lm is to the left of Ls and "-" when Lm is to the right of Ls. Step 7: Calculate the indication error △L1 of the first target detection point of the inspected steel tape: △L1=L1+ Lg+Lx1-Lb1 Step 7: Start the test at the second target detection point at the 2000mm mark: The second target detection point of the inspected steel tape is Lb2 = 2000mm. When the electric rotary table reaches the "detection position", the horizontal target distance it needs to rotate is Lx'2, which is 1000mm. At this time, the motor of the electric rotary table reaches the target horizontal distance Lx'2 = 1000mm through closed-loop control. At this time, the actual horizontal distance rotated is Lx2. The actual distance of the standard scale line Ls displayed on the screen is Ls = Lg + Lx1 + Lx2. According to step 6, the distance between Lm and the standard scale line Ls is L2. The indication error of the second target detection point is △L2: △L2= L2+ Lg+Lx1+ Lx2-Lb2; Similarly, according to the JJG 4-2015 steel tape measurement calibration requirements, complete the remaining test points meter by meter, and calculate the indication error according to the formula in step seven. After the test is completed, the electric rotary table reverses to the origin.

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