A mobile electronic balance automatic calibration device and method

Abstract

An automatic calibration device and calibration method for an electronic balance, the calibration device includes: an operating platform, a manipulator and a control system, the operating platform includes at least two or more workstations placed side by side, each of which can be used to place an electronic balance to be tested; the manipulator includes at least a mechanical arm, a claw clamp and a driving device; the control system is respectively connected to the mechanical arm and the driving device by signal; it also includes an AGV trolley suitable for installing and transporting the manipulator and a mobile door connected to the control system by signal; each of the workstations includes at least a side wall and an opening; the mobile door is controlled by the door opening / closing command of the control system to move, the AGV trolley is controlled by the movement command of the control system, and the manipulator is controlled by the calibration command of the control system to complete the calibration operation. The present invention combines a mobile robot and a visual recognition system to realize the automatic calibration of an electronic balance, which effectively improves the calibration efficiency.

Description

Technical Field

[0001] The invention relates to the field of metrological verification of non-automatic weighing instrument equipment, and in particular to an automatic verification device and method for a mobile electronic balance. Background Art

[0002] Electronic balances have the advantages of intuitive display, strong resolution, small size, and fast response. They are widely used in trade, environmental protection, biology, chemistry, medicine, food and other fields. The accuracy of electronic balance measurement is related to the credibility and reliability of related applications in the above fields. Therefore, electronic balances must be calibrated periodically to ensure the accuracy and reliability of electronic balance measurement. Every year, more than one million electronic balances need to be calibrated by metrology technical institutions at all levels to ensure the accuracy of electronic balance measurement.

[0003] At present, the calibration of electronic balances is basically carried out manually, that is, electronic balance calibrators use tweezers to pick up weights and calibrate the electronic balance for indication error, repeatability error, and eccentric load error according to JJG1036 "Electronic Balance Calibration Procedure". Since electronic balances are instruments with large usage, manual calibration brings a large workload to calibrators. At the same time, due to the fatigue of calibrators, different people have different working methods, which will bring large human errors to the calibration of electronic balances. Therefore, it is urgent to replace manual calibration with automatic calibration, so as to improve the accuracy and consistency of calibration results while improving calibration efficiency.

[0004] Chinese patent CN201420825003.4 discloses an online calibration device for electronic scales, including a tank, a support seat, an electronic scale, a first hydraulic cylinder, a bracket, a weight hanger, a weight group, a flatbed car and a contact switch group. The liquid container and the calibration weight are lifted by the hydraulic cylinder to realize automatic lifting of the liquid container; the calibration of the electronic scale is completed by combining the contact switch with the hanging weight. However, the automatic calibration equipment of the electronic scale can generally only calibrate the indication error of a single electronic scale. It uses a simple loading structure to load a string of weights connected in the first place onto the electronic scale pan in sequence by the first contact first load method, and calibrate the indication of the electronic scale. This method has a single function, fixed weight type and loading method, and a simple operation form. It is not suitable for the full-item calibration of the indication error, eccentric load error and repeatability error of the electronic balance.

[0005] Chinese patent CN201910515096.8 discloses a mobile electronic balance automatic calibration device, including a machine base, a manipulator and a control system. The manipulator includes a motion mechanism, a claw clamp and a driving device. The motion mechanism is installed on the machine base, the claw clamp is installed on the motion mechanism and moves through the movement of the motion mechanism. The driving device is connected to the claw clamp and is used to drive the claw clamp to achieve clamping action. The control system is connected to the motion mechanism signal to control the motion of the motion mechanism, and the control system is connected to the driving device signal to control the operation of the driving device. The motion mechanism is also provided with a distance sensor and a visual system, and the distance sensor is connected to the control system signal to detect the distance between the claw clamp and the electronic balance pan. The invention uses a manipulator combined with a visual system to automatically calibrate the electronic balance, which can replace the manual calibration method, reduce the workload and human errors, and improve work efficiency and reliability. However, this invention arranges the calibration platform in a way that the balance to be tested is arranged around the robot arm, the number of electronic balances calibrated at a single time is small, and because the robot arm can only rotate around a fixed center of a circle, the calibration range is limited, and the scene applicability is not flexible enough. In addition, since an open workbench is used for calibration, there is no protection of windproof equipment and the measurement results are greatly affected by airflow. Summary of the invention

[0006] In view of one or more of the above defects or improvement needs of the prior art, the present invention provides a mobile robot electronic balance automatic calibration device and an operation method. Automated Guided Vehicle (AGV), also commonly referred to as AGV, refers to a transport vehicle equipped with an electromagnetic or optical automatic navigation device, capable of traveling along a specified navigation path, with safety protection and various transfer functions, and is a type of mobile robot.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a method for automatic calibration of a mobile electronic balance, comprising:

[0008] A mobile electronic balance automatic calibration device includes an operating platform, a manipulator, a control system, an AGV trolley suitable for installing and transporting the manipulator, and a movable door connected to the control system signal. The operating platform includes at least a reference surface that is in a horizontal position during automatic calibration. The reference surface is provided with a placement area suitable for placing samples to be tested. The placement area includes at least two or more workstations placed side by side, and each of the workstations can be placed in an electronic balance to be tested. The operating platform can be a marble platform or a metal platform and has good flatness and levelness, which can ensure that the electronic balance placed on the operating platform is stable and not affected by external vibrations and the movement of the AGV trolley. Some operating platforms can also be equipped with a leveling device to ensure the levelness of the reference surface during calibration.

[0009] As a further improvement of the present invention, the manipulator comprises at least a manipulator arm, a gripper and a drive device; the control system is signal-connected to the manipulator arm and the drive device respectively.

[0010] As a further improvement of the present invention, the workstations are arranged in a matrix on the placement area, each of the workstations includes at least a top wall, a side wall and an opening, and two adjacent workstations are connected to each other or share a side wall; the movable door is controlled by the opening / closing door command of the control system to move so as to open / cover the opening of the workstation.

[0011] As a further improvement of the present invention, a distance sensor and a positioning camera are installed at the end of the mechanical arm, and the distance sensor is connected to the control system signal to detect the distance between the claw clamp and the electronic balance pan. The distance sensor can be a laser distance sensor, and the distance sensor feeds back the distance between the claw clamp and the pan to the control system. According to the distance information fed back by the distance sensor and the pan position, shape, and size information fed back by the positioning camera, the control system can control the manipulator to place the weight on the pan.

[0012] As a further improvement of the present invention, the positioning camera is connected to the control system signal to determine the shape of the scale pan and the position of the weight during subsequent detection.

[0013] As a further improvement of the present invention, each of the workstations is equipped with a reading camera, and the reading camera is connected to the control system signal for photographing and reading the displayed reading of the electronic balance. Compared with the single camera previously installed on the manipulator, the calibration method using a positioning camera and a reading camera can more reasonably optimize the calibration process. Before, each time the weights were placed in sequence, the manipulator had to move to the reading position for reading. If the weights were placed N times, it would have to move N times, which would increase the complexity of the entire process. Now, two separate cameras are used for reading and positioning, one for positioning and the other for reading. The manipulator does not need to move to the reading position for reading. After the weights are placed on the balance, the separate camera can read directly, simplifying the process and making the calibration process more reasonable.

[0014] The testing method comprises the following steps:

[0015] S1. Place the electronic balance to be inspected in the workstation in sequence and record information, including the working condition information and workstation information of the balance to be inspected, the working condition information includes: the model specification, grade, range, and actual graduation value of the electronic balance to be inspected; the workstation information includes: the workstation number and order of the workstations to be inspected in sequence;

[0016] S2. entering the operating condition information recorded in step S1 into the control system;

[0017] S3. The control system calculates the turning point of the segmented error of the weighing point during the calibration process of the electronic balance to be tested according to the working condition information of the electronic balance to be tested, and then determines the corresponding weight mass and the error limit of each weighing point during the measurement of the indication error, repeatability error and eccentric load error; the control system also calculates the moving path of the AGV according to the workstation information of the electronic balance to be tested;

[0018] S4. The control system sends a movement instruction to the AGV car, and the AGV car moves to the station where the first electronic balance to be inspected is stored;

[0019] S5. The control system sends a door opening command to the movable door, the movable door executes the door opening command, and the movable door moves to the other station;

[0020] S6. The control system sends a calibration instruction to the manipulator, and the manipulator executes the calibration instruction to calibrate the electronic balance to be inspected at the current station; during the calibration process, each time the manipulator places a weight, the movable door moves to the other stations, and when the reading camera reads, the movable door moves to the current station to isolate the airflow;

[0021] S7. After the verification is completed, the control system issues a door closing command to the movable door, and the movable door moves to other stations that do not block the next detection station;

[0022] S8. The control system sends a movement instruction to the AGV car, and the AGV car moves to the station where the next electronic balance to be inspected is stored;

[0023] S9. Repeat steps S5-S8 until the calibration of all electronic balances to be inspected is completed.

[0024] As a further improvement of the present invention, the top wall and the side walls are enclosed to form a wind shield to prevent the influence of airflow on the measurement of the electronic balance and reduce errors.

[0025] As a further improvement of the present invention, during calibration, the movable door keeps covering the opening, further providing a windproof and dustproof environment for the calibration of the electronic balance to be tested. During actual calibration, due to the influence of external airflow, after the weight is placed, the calibration reading is affected by the fluctuating environment, and the calibration reading tends to be stable for a long time. When the manipulator places the weight, the movable door moves to the adjacent workstation. After the manipulator finishes placing the weight, the movable door returns to the current workstation and opens again when the weight is placed next time, which can prevent the influence of airflow on the measurement of the electronic balance and speed up the time for the reading to stabilize.

[0026] As a further improvement of the present invention, the AGV is controlled by the movement command of the control system to move to the corresponding workstation to complete the calibration operation; the manipulator is controlled by the calibration command of the control system to complete the calibration operation under the cooperation of the opening and closing of the moving door. Since the movement of the AGV is more flexible, compared with the traditional calibration method in which the manipulator is fixed and only rotates around a fixed center of a circle to perform single-machine calibration, the calibration range is wider, and multi-station calibration is adopted, one is moved and one is tested, and the process is reasonable.

[0027] As a further improvement of the present invention, the door opening / closing instructions of the movable door include: an opening instruction of moving to the adjacent workstation to open the current workstation, and a door closing instruction of returning to the current workstation to close the opening of the workstation.

[0028] As a further improvement of the present invention, a guide rail structure suitable for guiding the movement of the movable door is further provided on the top wall, and the guide rail structure at least covers the width of two of the workstations placed side by side.

[0029] As a further improvement of the present invention, a weight bracket is also provided on the AGV trolley, and the weight is placed on the weight bracket. The weight bracket adopts a multi-layer stepped structure, and each layer of the multi-layer stepped structure is provided with weight slots of different sizes. The weight is placed in the weight slots, and the size of the weight slots matches the weights for accurate placement of the weights.

[0030] As a further improvement of the present invention, the claw clamp is installed at the end of the mechanical arm, and the position adjustment in the current workstation is achieved through the movement of the mechanical arm.

[0031] As a further improvement of the present invention, the mechanical arm is a vertical multi-joint mechanical arm, which has strong spatial movement ability, flexible operation, and can accurately place the weight position.

[0032] As a further improvement of the present invention, the driving device is connected to the claw clamp and is suitable for driving the claw clamp to clamp the weight.

[0033] As a further improvement of the present invention, the claw clamp is a composite claw clamp, the front end portion of the claw clamp is used to clamp large weights, and the middle portion of the claw clamp is used to clamp small weights.

[0034] As a further improvement of the present invention, the weights are special weights, which are weights produced for easy clamping by claw clamps. The special weights are in the shape of a cylinder, with a protrusion at the upper end and a groove at the lower end. The protrusions and grooves of two special weights can cooperate with each other, which is conducive to more stability when multiple weights are stacked. The side of the special weight is provided with an annular groove, which is conducive to clamping by the claw clamp.

[0035] As a further improvement of the present invention, each time the claw clamp completes a verification action, the control system controls the movable door to execute a corresponding door opening / closing instruction, so that when the weight is placed in the workstation for reading, the movable door closes the opening.

[0036] As a further improvement of the present invention, the control system includes a robotic arm controller, a PLC and an industrial computer; the robotic arm controller is connected to the robotic arm signal for controlling the movement of the robotic arm; the PLC is connected to the drive device signal for controlling the operation of the drive device; the industrial computer is connected to the AGV car signal for controlling the movement of the AGV car; the industrial computer is connected to the mobile door signal for controlling the opening and closing of the mobile door.

[0037] As a further improvement of the present invention, the industrial computer is connected to the distance measuring sensor signal, and the distance measuring sensor feeds back the detected distance signal between the claw clamp and the electronic balance pan to the industrial computer; the industrial computer is connected to the positioning camera signal, and the positioning camera feeds back the image information of the electronic balance pan to the industrial computer, and the industrial computer calculates the shape and size of the pan and the position of the weights based on the image information; the industrial computer is connected to the reading camera signal for receiving the data signal fed back by the reading camera; the built-in electronic balance calibration workflow of the industrial computer is used to complete the calibration of the electronic balance indication error, repeatability error and overload error.

[0038] As a further improvement of the present invention, the control system can control the AGV to move to the workstation where the electronic balance is placed, and calculate the mass of weights required for the calibration of the three items of indication error, repeatability error and eccentric load error of the electronic balance according to the model specifications, range, grade and actual graduation value of the electronic balance, and then control the manipulator to perform corresponding calibration operations.

[0039] As a further improvement of the present invention, the control system is a control system based on a desktop computer. The control system controls the AGV car to move to the operating station where the electronic balance is placed, and then controls the manipulator, moving door, ranging sensor, positioning camera, and reading camera to operate, and calibrate the indication error, repeatability error, and overload error of the electronic balance.

[0040] As a further improvement of the present invention, the verification instruction includes:

[0041] S6.1 The manipulator moves so that the claw moves to above the electronic balance to be inspected at the workstation;

[0042] S6.2 The distance measuring sensor detects the distance between the claw clamp and the electronic balance pan and feeds back the distance information to the control system;

[0043] S6.3 The positioning camera captures the shape and size of the electronic balance pan and feeds the information back to the control system;

[0044] S6.4 The control system calculates the position of the weight according to the information obtained by feedback;

[0045] S6.5 completes the verification of indication error, repeatability error and eccentric load error in sequence according to the verification process.

[0046] Compared with the prior art, the present invention has the following beneficial technical effects:

[0047] On the one hand, compared with the original automatic calibration device in which the manipulator is stationary and the electronic balance to be inspected is axially surrounded, the present invention can move with the mobile AGV, and inspect one by one as it moves, so the automated calibration has high efficiency and flexible operation.

[0048] On the other hand, traditional calibration platforms are mostly open, which are affected by airflow and dust, and the measurement results are greatly affected. The present invention installs a wind shield and a movable door on the operating platform, and the control system further controls the opening and closing of the movable door, thereby reducing the impact of airflow in the operating environment on the calibration readings and the reading stability time.

[0049] On the other hand, the traditional calibration platform is a single machine, but now it is a mobile robot, which is not limited to a single machine, but can be used for multi-station calibration. The calibration process is standardized and unified, which effectively avoids random errors caused by human operation.

[0050] On the other hand, the traditional calibration platform is a single camera installed on the robot for positioning and reading, while the present invention is a multi-camera, one installed on the robot for positioning, and then each electronic balance detection station also has one for reading, which simplifies the operation process and optimizes the calibration steps.

[0051] On the other hand, the present invention can realize the automatic calibration of electronic balances by combining the mobile robot and the visual recognition system, thereby reducing the workload of calibration personnel and effectively improving the efficiency of electronic balance calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 It is a structural schematic diagram of the present invention.

[0054] Figure 2It is a structural diagram of a mobile robot.

[0055] Reference numerals:

[0056] 1—driving device, 2—claw clamp, 3—mechanical arm, 4—control system, 5—weight, 6—weight bracket, 7—AGV trolley, 8—positioning camera, 9—distance measuring sensor, 10—reading camera, 11—electronic balance, 12—moving door, 13—wind shield, 14—operating platform, 15—reference surface, 16—side wall, 17—top wall, 18—opening. DETAILED DESCRIPTION

[0057] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0058] It should be noted that the terms "installed", "set", "provided with", "connected", "connected", and "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] When the installation method is described as "connected" or "connected", it can be directly connected or indirectly connected through a central component. The words "vertical", "horizontal", "parallel" and the like referred to herein refer to a roughly vertical or roughly horizontal state within a reasonable error range, and do not have to be very precise; "horizontal" and "vertical" are also only for the convenience of describing the relative position relationship between the components. Unless otherwise indicated in the present invention, a component "provided with", "provided on", "provided in", or "connected to" another component does not exclude that the two components are an integrated structure.

[0060] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0061] See also Figures 1 to 2As shown, the electronic balance automatic calibration device of this embodiment includes an operating platform 14, an AGV trolley 7, a manipulator and a control system 4, the manipulator includes a mechanical arm 3, a claw clamp 2 and a driving device 1, the mechanical arm 3 is installed on the AGV trolley 7 and moves through the movement of the AGV trolley 7, the claw clamp 2 is installed at the end of the mechanical arm 3 and moves through the movement of the mechanical arm 3, the driving device 1 is connected to the claw clamp 2 and is used to drive the claw clamp 2 to clamp the weight 5, the control system 4 is connected to the mechanical arm 3 signal for controlling the movement of the mechanical arm 3, and the control system 4 is connected to the driving device 1 signal for controlling the operation of the driving device.

[0062] like Figure 2 As shown, a distance sensor 9 and a positioning camera 8 are also installed at the end of the robotic arm 3. The distance sensor 9 is connected to the control system signal 4 for detecting the distance between the claw clamp 2 and the scale pan of the electronic balance 11. The positioning camera 8 is connected to the control system 4 signal for determining the shape of the scale pan and the position of the weight 5 during subsequent detection.

[0063] The AGV trolley 7 is equipped with a weight bracket 6 and a weight 5, and the weight 5 is placed on the weight bracket 6. The weight bracket 6 adopts a multi-layer stepped structure. Each layer of the multi-layer stepped structure is provided with a weight slot of different sizes. The weight 5 is placed in the weight slot. The size of the weight slot matches the weight 6 for accurate placement of the weight 5.

[0064] The weight 5 is a special weight, which is produced for easy clamping of the claw clamp 2. The special weight is in the shape of a cylinder, with a protrusion on the upper end and a groove on the lower end. The protrusions and grooves of the two special weights can cooperate with each other, which is conducive to more stability when multiple weights 5 are stacked. The side of the special weight is provided with an annular groove, which is conducive to clamping by the claw clamp 2.

[0065] The electronic balance 11 is placed on a separate operating platform 14. The operating platform 14 includes a reference surface that is in a horizontal position during automatic calibration. The reference surface is provided with a placement area suitable for placing samples to be tested. The placement area includes multiple workstations placed side by side, and each workstation is provided with an electronic balance 11. The operating platform 14 can be a marble platform or a metal platform and has good flatness and levelness, which can ensure that the electronic balance 11 placed on the operating platform 14 is stable and not affected by external vibrations and the movement of the AGV trolley 7. In other embodiments, the operating platform 14 can also be equipped with a leveling device to ensure the levelness of the reference surface 15 during calibration.

[0066] The workstations are arranged in a matrix on the placement area, and each workstation includes at least a top wall 16, a side wall 17, and an opening 18. Two adjacent workstations share a side wall 17. In some other embodiments, the side walls 17 of two adjacent workstations can be connected and fixed by a connecting structure. The top wall 16 and the side wall 17 enclose a windshield 13, which separates the workstations of the electronic balance 11 to prevent the airflow from affecting the measurement of the electronic balance 11 and reduce errors.

[0067] A guide rail structure suitable for guiding the movement of the movable door 12 is also provided on the top wall 16, and the guide rail structure covers the width of all the workstations placed side by side.

[0068] The wind shield 13 has a movable door 12, and the movable door 12 is connected to the control system 4 signal for controlling the position of the movable door 12. When the manipulator places the weight, the movable door moves to the next station. After the manipulator finishes placing the weight 5, the movable door returns to the current station, covering the opening 18 of the current station, and opens again when the weight 5 is placed next time, preventing the airflow from affecting the measurement of the electronic balance 11, which can speed up the time for the reading to stabilize.

[0069] A reading camera 10 is installed at the operating station of each electronic balance 11 . The reading camera 10 is connected to the control system 4 by signal and is used to photograph and read the displayed reading of the electronic balance 11 .

[0070] The control system 4 can control the AGV trolley 7 to move to the workstation where the electronic balance 11 is placed, and calculate the weight mass required for the calibration of the three items of indication error, repeatability error and eccentric load error of the electronic balance 11 according to the model specification, range, grade and actual graduation value of the electronic balance 11, and then control the manipulator to perform the corresponding calibration operation.

[0071] The mechanical arm 3 is a vertical multi-joint mechanical arm, which has strong spatial movement ability, flexible operation, and can accurately place the weight position.

[0072] The claw clamp 2 is a composite claw clamp, the front end of the claw clamp 2 is used to clamp the large weight, and the middle part of the claw clamp 2 is used to clamp the small weight.

[0073] The distance measuring sensor 9 uses a laser distance measuring sensor. The distance measuring sensor 9 feeds back the distance between the claw clamp 2 and the scale pan of the electronic balance 11 to the control system 4. According to the distance information fed back by the distance measuring sensor 9 and the scale pan position, shape and size information fed back by the positioning camera 8, the control system 4 can control the manipulator to place the weight 5 on the scale pan.

[0074] The control system 4 includes a robot controller, a PLC and an industrial computer; the robot controller is connected to the robot 3 by signal to control the movement of the robot 3; the PLC is connected to the drive device 1 by signal to control the operation of the drive device 1; the industrial computer is connected to the AGV trolley 7 by signal to control the movement of the AGV trolley 7; the industrial computer is connected to the mobile door by signal to control the opening and closing of the mobile door; the industrial computer is connected to the distance sensor 9 by signal, and the distance sensor 9 feeds back the detected distance signal between the claw clamp 2 and the electronic balance 11 scale pan to the industrial computer; the industrial computer is connected to the positioning camera 8 by signal, and the positioning camera 8 feeds back the image information of the electronic balance 11 scale pan to the industrial computer, and the industrial computer calculates the shape and size of the scale pan and the position of the weight 5 according to the image information; the industrial computer is connected to the reading camera 10 by signal to receive the data signal fed back by the reading camera 10; the built-in electronic balance calibration workflow of the industrial computer is used to complete the calibration of the electronic balance indication error, repeatability error and eccentric load error.

[0075] The control system 4 is a control system based on a desktop computer. The control system 4 controls the AGV trolley 7 to move to the operating station where the electronic balance 11 is placed, and then controls the manipulator, moving door, distance sensor 9, positioning camera 8, and reading camera 10 to work, and calibrates the indication error, repeatability error, and overload error of the electronic balance 11.

[0076] The working principle of this embodiment is as follows:

[0077] Several electronic balances 11 are placed on the operating stations in turn, and the model specifications, grade, range, and actual graduation value information of the electronic balances on the corresponding operating stations are input into the control system 4. The control system 4 calculates the mass of the weights corresponding to the indication error, repeatability error, and eccentric load error of the electronic balance calibration and the error limit of each weighing point based on the information of the electronic balance 11.

[0078] After the calculation is completed, the AGV trolley 7 moves to the first operating station according to the instruction, the mobile door receives the door opening instruction and moves to the second operating station, the manipulator moves to move the claw clamp 2 to the top of the electronic balance 11, the distance sensor 9 detects the distance between the claw clamp 2 and the scale pan of the electronic balance 11 and feeds the distance information back to the control system 4, the positioning camera 8 captures the shape and size of the scale pan of the electronic balance 11 and feeds the information back to the control system 4, and the control system 4 calculates the position of the weight 5 based on the feedback information; wherein, when the indication error and repeatability error are tested, the position of the weight 5 is the center of the scale pan of the electronic balance 11 During the eccentric load error calibration, the weight 5 is placed at a position halfway from the center to the edge of the electronic balance 11 scale pan; after determining the position of the weight 5, the indication error, repeatability error, and eccentric load error calibration are completed in sequence according to the work flow; before each placement of the weight 5, the moving door is opened, and after the manipulator places the weight 5 at the corresponding position, the moving door is closed, and the reading camera 8 waits until the indication of the electronic balance 11 is stable, reads the reading of the electronic balance 11, and stores the reading in the control system 4. After the calibration is completed, the calibration result will be judged. If the error does not exceed the maximum allowable value, it is judged as qualified, otherwise it is judged as unqualified.

[0079] After completing the calibration of the first operating station, the AGV 7 moves to the second operating station and starts to perform the calibration work, and then moves to the third, fourth, and fifth stations in turn to perform the calibration work until the calibration of the electronic balance 11 at all stations is completed.

[0080] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A mobile electronic balance automatic calibration method, characterized in that: include A mobile electronic balance automatic calibration device, comprising an operating platform, a manipulator, a control system, an AGV trolley suitable for installing and transporting the manipulator, and a movable door connected to the control system by signal, wherein the operating platform at least comprises a reference surface which is in a horizontal position during automatic calibration, and a placement area suitable for placing samples to be tested is provided on the reference surface, and the placement area comprises at least two or more workstations placed side by side, and each of the workstations can be used to place an electronic balance to be tested; the manipulator at least comprises a mechanical arm, a claw clamp, and a driving device; the control system is respectively connected to the mechanical arm and the driving device by signal; The workstations are arranged in a matrix on the placement area, each of the workstations at least comprises a top wall, a side wall and an opening, and two adjacent workstations are connected to each other or share a side wall; the movable door is controlled by the door opening / closing command of the control system to move so as to open / cover the opening of the workstation; the AGV trolley is controlled by the movement command of the control system to move to the front of the corresponding workstation to complete the verification operation; the manipulator is controlled by the verification command of the control system to complete the verification operation under the cooperation of the opening and closing of the movable door; The end of the mechanical arm is equipped with a distance sensor and a positioning camera, the distance sensor is connected to the control system signal to detect the distance between the claw clamp and the electronic balance pan; the positioning camera is connected to the control system signal to determine the shape of the pan and the position of the weights during subsequent detection; Each of the workstations is equipped with a reading camera, which is connected to the control system signal for photographing and reading the display reading of the electronic balance; The verification method comprises the following steps: S1. Place the electronic balance to be inspected in the workstation in turn and record the information; The information includes the working condition information and work position information of the balance to be calibrated. The working condition information includes: the model specification, grade, range, and actual graduation value of the electronic balance to be inspected; The workstation information includes: the workstation numbers and order of the workstations to be tested in sequence; S2. Entering the information recorded in step S1 into the control system; S3. The control system calculates the turning point of the segmented error of the weighing point during the calibration process of the electronic balance to be tested according to the working condition information of the electronic balance to be tested, and then determines the corresponding weight mass and the error limit of each weighing point during the measurement of the indication error, repeatability error and eccentric load error; The control system also calculates the moving path of the AGV according to the workstation information of the electronic balance to be inspected; S4. The control system sends a movement instruction to the AGV car, and the AGV car moves to the station where the first electronic balance to be inspected is stored; S5. The control system sends a door opening command to the movable door, the movable door executes the door opening command, and the movable door moves to the other station; S6. The control system issues a calibration instruction to the manipulator, and the manipulator executes the calibration instruction to calibrate the electronic balance to be inspected at the current station; During the calibration process, each time the manipulator places a weight, the movable door moves to the other workstations, and when the reading camera reads, the movable door moves to the current workstation to isolate the airflow; S7. After the verification is completed, the control system issues a door closing command to the movable door, and the movable door moves to other stations that do not block the next detection station; S8. The control system sends a movement instruction to the AGV car, and the AGV car moves to the station where the next electronic balance to be inspected is stored; S9. Repeat steps S5-S8 until the calibration of all electronic balances to be inspected is completed.

2. The method for automatic verification of a mobile electronic balance according to claim 1, characterized in that: The top wall and the side walls are combined to form a wind shield; during inspection, the movable door keeps covering the opening.

3. The method for automatic verification of a mobile electronic balance according to claim 2, characterized in that: The door opening / closing instructions of the movable door include: an opening instruction of moving to the adjacent workstation to open the current workstation, and a door closing instruction of returning to the current workstation to cover the opening of the workstation; And / or, the top wall is further provided with a guide rail structure suitable for guiding the movement of the movable door, and the guide rail structure at least covers the width of two of the workstations placed side by side.

4. The method for automatic verification of a mobile electronic balance according to claim 3, characterized in that: The AGV trolley is also provided with a weight bracket, on which the weight is placed. The weight bracket adopts a multi-layer stepped structure, and each layer of the multi-layer stepped structure is provided with weight slots of different sizes. The weight is placed in the weight slots, and the size of the weight slots matches the weight for accurate placement of the weight.

5. The method for automatic verification of a mobile electronic balance according to claim 4, characterized in that: The claw clamp is installed at the end of the mechanical arm, and the position adjustment in the current workstation is achieved through the movement of the mechanical arm; The driving device is connected to the claw clamp and is suitable for driving the claw clamp to clamp the weight; the front end of the claw clamp is suitable for clamping large weights, and the middle part of the claw clamp is suitable for clamping small weights.

6. The method for automatic verification of a mobile electronic balance according to claim 5, characterized in that: Each time the claw clamp completes an action of clamping and placing the weight, the control system controls the movable door to execute a corresponding door opening / closing instruction, and keeps the movable door covering the opening when the weight is located in the work station for reading.

7. The method for automatic verification of a mobile electronic balance according to claim 1, characterized in that: The verification instructions include: S6.1 The manipulator moves so that the claw moves to above the electronic balance to be inspected at the workstation; S6.2 The distance measuring sensor detects the distance between the claw clamp and the electronic balance pan and feeds back the distance information to the control system; S6.3 The positioning camera captures the shape and size of the electronic balance pan and feeds the information back to the control system; S6.4 The control system calculates the position of the weight according to the information obtained by feedback; S6.5 completes the verification of indication error, repeatability error and eccentric load error in sequence according to the verification process.

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