Fixed platform and method for automatically measuring the backlash of a gear wheel for use with an industrial robot

Abstract

A stationary platform (3) comprises a base plate (32), a stationary part (34) provided on the base plate (32), a counterweight (36) coupled to a terminal arm (10) of an industrial robot (1), and a cylinder (38) provided on the base plate (32) adjacent to the stationary part (34). The cylinder (38) comprises a plunger (380) configured to move along a first direction (L1) to clamp the counterweight (36) when the counterweight (36) is coupled to the stationary part (34). A method of automatically measuring backlash of a gear (400) is also provided.

Description

Technical Field

[0001] Example embodiments of the present disclosure relate generally to the field of industrial robots, and more particularly to a fixed platform and a method for automatically measuring backlash of gears. Background Art

[0002] In the system architecture of an industrial robot, the robot's arm is driven by a power source, such as a servo motor and corresponding gears. While gears have proven to offer the highest transmission efficiency in practice, they also present a problem: gear backlash. Because gear backlash is a key indicator of gear accuracy, regular inspection and testing are crucial to promptly detect and analyze faults. Consequently, real-time monitoring of industrial robot performance remains a challenge. Summary of the Invention

[0003] Generally speaking, example embodiments of the present disclosure provide a stationary platform to assist in measuring backlash of gears.

[0004] In a first aspect, a fixed platform is provided. The fixed platform includes: a base plate; a fixed component disposed on the base plate; a counterweight coupled to an end arm of an industrial robot; and a cylinder disposed on the base plate and adjacent to the fixed component. The cylinder includes a plunger configured to move in a first direction to clamp the counterweight when the counterweight is coupled to the fixed component.

[0005] According to example embodiments, a fixed platform may be used to automatically measure the backlash of a gear without manual intervention, thereby improving measurement efficiency.

[0006] In some example embodiments, the fixing component includes a base portion coupled to a substrate; a first protrusion extending from the base portion; and a second protrusion extending from the base portion, wherein the second protrusion is spaced apart from the first protrusion along a second direction perpendicular to the first direction to form a gap between the first protrusion and the second protrusion. In these embodiments, the end arm of the industrial robot can automatically follow a predetermined path to fully insert the counterweight into the gap of the fixing component.

[0007] In some example embodiments, the plunger includes a plunger face facing the first protrusion and the second protrusion, and the first protrusion and the second protrusion each include a protrusion face facing the plunger, wherein the protrusion face is parallel to the plunger face, so that when the balancing weight is coupled to the fixed component, the balancing weight can be clamped between the protrusion face and the plunger face. With these embodiments, the balancing weight can be securely clamped.

[0008] In some example embodiments, the counterweight is coupled to the end arm of the industrial robot via a link, and wherein the link can be accommodated within a gap when the counterweight is coupled to the fixed component, such that the counterweight can be supported by the first protrusion and the second protrusion. For these embodiments, the measurement test can be implemented in a cost-effective manner.

[0009] In some example embodiments, the plunger can be hydraulically, pneumatically or electrically actuated. For these embodiments, the user can use the fixed platform to measure the backlash of the gear in multiple ways.

[0010] In some example embodiments, the fixed platform further comprises: a base coupled to the stationary body, wherein the base plate is coupled to the base. For these embodiments, the fixed platform can be firmly fixed in place.

[0011] In some example embodiments, the fixed platform further comprises: an image capture module disposed adjacent to the fixed component and configured to assist in positioning of the counterweight onto the fixed component. For these embodiments, collisions can be avoided when actuating the counterweight under a predetermined route.

[0012] In some example embodiments, the stationary body is the ground. For these embodiments, the fixed platform can be firmly fixed to ensure accurate measurement results.

[0013] In a second aspect, a method of automatically measuring the backlash of a gear is provided. The gear is coupled between an input shaft and an output shaft, the input shaft being coupled to a motor. The method comprises: fixing the output shaft by means of a fixed platform; causing the motor to provide a torque to the input shaft to allow the gear to rotate by an angle under the torque; and obtaining the torque and the degree of rotation of the gear; and determining the backlash of the gear based on the torque and the degree of rotation. For these embodiments, the process reduces the cost of manpower and material, reduces errors and improves test frequency and utilization.

[0014] In some example embodiments, the fixing of the output shaft is achieved by the fixed platform of the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0015] The above and other objects, features and advantages of the example embodiments disclosed herein will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. In the drawings, several example embodiments disclosed herein are illustrated by way of example and not limitation in which:

[0016] Figure 1 illustrates the backlash in a transmission gear;

[0017] Figure 2 illustrates the principle of measuring the backlash of a gear according to a conventional method;

[0018] Figure 3 An example hysteresis curve is illustrated;

[0019] Figure 4 The principle of measuring the backlash of a gear according to the present disclosure is illustrated;

[0020] Figure 5 illustrates a schematic diagram of an industrial robot according to an example embodiment of the present disclosure;

[0021] Figure 6 Pictured Figure 5 Side view of an industrial robot;

[0022] Figure 7 The diagram shows Figure 5 a schematic diagram of a fixed platform for use with an industrial robot; and

[0023] Figure 8 A method for automatically measuring backlash of a gear according to the present disclosure is illustrated.

[0024] Throughout the drawings, the same or similar reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0025] The principles of the present disclosure will now be described with reference to some exemplary embodiments. It will be understood that these embodiments are described for illustration only and for the purpose of helping those skilled in the art to understand and implement the present disclosure, and no limitation to the scope of the present disclosure is recommended. The disclosure described herein can be implemented in a variety of ways except as described below.

[0026] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0027] References in this disclosure to "one embodiment," "an embodiment," "an example embodiment," etc., indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment will necessarily include that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is contemplated that it is within the knowledge of those skilled in the art to apply such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described.

[0028] It should be understood that although the terms "first" and "second" and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are merely used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the example embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items.

[0029] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the example embodiments. As used herein, unless the context clearly indicates otherwise, the singular forms "a," "an," and "the" are intended to include the plural forms as well. It will be further understood that when used herein, the terms "comprise," "including," "having," "comprising," "containing," and / or "comprising" specify the presence of stated features, elements, and / or components, etc., but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0030] As mentioned above, the backlash of the gears should be monitored in real time to ensure the performance of the corresponding industrial robot. The details of the present disclosure will be described later.

[0031] Figure 1 The figure illustrates backlash in the transmission gears. Backlash (indicated by D) exists between two gears 102 and 104. Gear 102 can be coupled to an input device (not shown), and gear 104 can be coupled to an output device (not shown). In this case, gear 102 operates as a driving gear, while gear 104 operates as a driven gear.

[0032] Many factors (e.g., gear wear) may cause backlash D. Gear wear of either gear 102, 104 will reduce its transmission accuracy, which causes transmission inaccuracy and reduces the service life of gears 102, 104. If the gap between gears 102, 104 is too large, the thickness of the gear teeth will be too small, which will affect the strength. Especially for gear transmission systems that need to achieve forward and reverse rotation, inappropriate backlash D will have a great impact during speed changes. It is easy to cause broken teeth and other faults. A large meshing gap may be due to processing or design problems. If there are no problems with part design and processing, a large meshing gap may be due to a large center distance error. In this case, the meshing of the gears is not in a normal state, which leads to increased wear, a reduced overlap coefficient, and reduced motion transmission accuracy.

[0033] Therefore, how to accurately measure the gear backlash is the key point to monitor the performance of the gear in real time.

[0034] Conventionally, many methods have been proposed to measure the backlash of gears. Figure 2 The diagram shows the principle of measuring the backlash of a gear according to the traditional method. Figure 2 As can be seen in FIG, the gear 400' is coupled to the motor 600' via the input shaft 401' and is coupled to the actuator 500' via the output shaft 402'. The actuator 500' may be a robotic arm of an industrial robot.

[0035] As shown in the figure, the traditional measurement method is to first fix the input end of gear 400'. The input end includes motor 600' and input shaft 401'. Next, force is continuously applied to the torque meter in both rotational directions at the output end of gear 400' to overcome friction in the gearbox and then gradually unload. The output end includes actuator 500' and output shaft 402'. Throughout this process, the input end of gear 400' will move at a small angle, which is called backlash. The equipment is used to record the angular profile that changes with torque. This results in a closed curve, which is called a hysteresis curve. Figure 3 An example hysteresis curve is shown. The hysteresis curve directly reflects the relationship between the force and displacement of the teeth of gear 400', which is considered a load-displacement curve. In the curve, it is possible to determine how much displacement occurs between the teeth under the action of a certain force.

[0036] In summary, the conventional method of measuring gear backlash is to fix the motor 600' and the input shaft 401', apply torque to the output end, and calculate the backlash value. However, a number of disadvantages may be significant.

[0037] For example, the test environment must be manually constructed for each robot axis. This involves a complex set of equipment, including force sensors, displacement sensors, and data acquisition cards. Furthermore, the frequent disassembly and assembly of the test equipment can introduce installation errors, compromising test accuracy. To make matters worse, applying torque to the output terminals is manual. This means the torque level cannot be precisely controlled, potentially risking damage to components.

[0038] To at least address the aforementioned deficiencies, the present disclosure proposes a novel method for automatically measuring backlash and a corresponding fixed platform. To address the limitations of current gear backlash testing methods, the present invention employs a novel, comprehensive automated technical testing solution that employs a different design concept than traditional methods.

[0039] The following will refer to Figures 4 to 8 Detailed description of example embodiments follows.

[0040] Figure 4 The diagram shows the principle of measuring the backlash of a gear according to the present disclosure. Figure 4As can be seen, gear 400 is coupled to motor 600 via input shaft 401 and to actuator 500 via output shaft 402. Unlike conventional methods, the present invention treats a fixed output as standard; the input applies a specific torque via the motor. The input comprises motor 600 and input shaft 401, and the output comprises actuator 500 and output shaft 402. Actuator 500 may be the arm of an industrial robot. By fixing actuator 500 and output shaft 402 while causing motor 600 and input shaft 401 to rotate, the system eliminates the need for any external measurement equipment, such as the torque meter and displacement sensor used in conventional methods. Instead, during measurement, motor 600 serves as the input, and signals within the robot controller can be collected to obtain angular displacement and torque in real time.

[0041] Figures 5 and 6 A schematic diagram and a side view of an industrial robot according to an example embodiment of the present disclosure are respectively illustrated.

[0042] like Figure 5 As shown in FIG, the fixed platform 3 generally includes a base plate 32, a fixed component 34, a counterweight 36, and a cylinder 38. The fixed component 34 and the cylinder 38 are disposed adjacent to each other on the base plate 32 and are used to clamp the counterweight 36, which is coupled to the terminal arm 10 of the industrial robot 1. The cylinder 38 includes a plunger 380 designed to move along a first direction L1. When the counterweight 36 is actuated to move adjacent to the fixed component 34, it can ultimately be positioned and securely clamped between the plunger 380 and the fixed component 34.

[0043] In other exemplary embodiments, the terminal arm 10 and the counterweight 36 can be moved in various ways. For example, the terminal arm 10 can be hydraulically, pneumatically, or electrically actuated to be positioned on the base plate 32 between the plunger 380 of the cylinder 38 and the fixed component 34. Since the entire fixed platform 3 can be operated for use with the terminal arm 10, the backlash of the gears can be continuously measured without any manual intervention.

[0044] In other exemplary embodiments, the plunger 380 can be hydraulically actuated. Also, in other exemplary embodiments, the plunger 380 can be pneumatically actuated. In other exemplary embodiments, the plunger 380 can be electrically actuated. With these embodiments, a user can use a stationary platform to measure the backlash of a gear in a variety of ways.

[0045] According to an exemplary embodiment of the present disclosure, the counterweight 36 and terminal arm 10 can automatically move to a desired position between the plunger 380 and the fixed member 34. In further exemplary embodiments, this movement can be performed along a path previously determined by experimentation or simulation.

[0046] In some exemplary embodiments, the counterweight 36 and the terminal arm 10 can be moved to a desired position using various postures. Through these postures, equations can be obtained under different measurement conditions. Based on these equations, the backlash of the gear 10 can be determined.

[0047] According to the present disclosure, measurements are performed with the counterweight 36 positioned at the end of the terminal arm 10 of the industrial robot 1 to verify the accuracy of the end positioning and fully investigate the impact of the rated load of the counterweight 36 on the kinematic performance of the industrial robot 1. After the measurement, backlash is measured to verify that the backlash is within an acceptable error range. This measurement method directly utilizes the counterweight 36 to cooperate with the fixed component 34, and the automatic movement of the industrial robot 1 aligns with a predefined path. The industrial robot 1 automatically secures its end using the counterweight 36. Following a set trajectory, the industrial robot 1 inserts the counterweight 36 into the slot in different postures, ensuring that a specific axis is well-held by changing the robot's posture. Furthermore, this posture ensures that the stiffness of the axis to be measured is maintained. Furthermore, different postures of the industrial robot 1 represent different gear meshing states. Therefore, backlash values ​​under different meshing conditions can be determined. By calculating the average value, a more comprehensive and integrated understanding of backlash analysis can be achieved.

[0048] In some exemplary embodiments, simple calculations can be used to reduce the overall system's degrees of freedom to zero. Once the terminal arm 10 of the industrial robot 1 is positioned and secured to the base plate 32, the industrial robot 1 remains stationary and immobile. According to exemplary embodiments, the fixed platform 3 suppresses movement between the arms within the entire system. In this way, the fixed platform 3 provides a mechanism for the output end of the gears connecting the arms to remain stationary. In this case, the motor 600 can apply a specified torque to measure the backlash of the gears, as discussed above.

[0049] Figure 7 The diagram shows Figure 5 Schematic diagram of a fixed platform 3 for use with an industrial robot 1. In the illustrated embodiment, the fixed member 34 may include a base portion 340 coupled to the base plate 32. A first protrusion 341 and a second protrusion 342 extend from the base portion 340. The second protrusion 342 is spaced apart from the first protrusion 341 along a second direction L2 perpendicular to the first direction L1, forming a gap S between the first protrusion 341 and the second protrusion 342.

[0050] refer to Figure 7In the illustrated embodiment, the plunger 380 may include a plunger face 385 facing the first protrusion 341 and the second protrusion 342. The first protrusion 341 and the second protrusion 342 each include a protrusion face 345 facing the plunger 380. The protrusion faces 345 are parallel to the plunger face 385. For these embodiments, when the balance weight 36 is actuated into the space between the protrusion faces 345 and the plunger face 385, the plunger 380 may move toward the protrusion faces 345. Once the plunger face 385 contacts the surface of the balance weight 36, the balance weight 36 may be securely clamped.

[0051] like Figure 5 As illustrated in the enlarged view of FIG, in some example embodiments, the balancing weight 36 may be coupled to the terminal arm 10 of the industrial robot 1 via a link 35. When the balancing weight 36 is coupled to the fixed component 34, the link 35 may be accommodated within the gap S. In this manner, the balancing weight 36 may be supported by the first protrusion 341 and the second protrusion 342 to ensure stable clamping.

[0052] like Figure 7 As shown in FIG, in some example embodiments, the fixed platform 3 further includes a base 37 coupled to the stationary body, and the base plate 32 is coupled to the base 37. In further embodiments, the stationary body can be the ground. For these embodiments, the fixed platform 3 can be securely fixed.

[0053] In some exemplary embodiments, the fixed platform 3 may further include an image capture module. This image capture module may be positioned adjacent to the fixed component 34. Over time, the planned route may become inaccurate due to, for example, loose components. For the embodiments discussed herein, the image capture module can accurately and in real time determine the position of the counterweight 36, thereby facilitating the positioning of the counterweight 36 on the fixed component 34.

[0054] In a second aspect, a method for automatically measuring the backlash of a gear 400 is provided. Gear 400 is coupled between an input shaft 401 and an output shaft 402, with input shaft 401 coupled to a motor 600. The method includes: securing output shaft 402 using the fixture 2 discussed above; causing motor 600 to apply torque to input shaft 401 to allow gear 400 to rotate by an angle under the torque; obtaining the torque and degree of rotation of gear 400; and determining the backlash of gear 400 based on the torque and degree of rotation. In some further exemplary embodiments, the above process may be performed multiple times to average the test results, thereby ensuring accuracy.

[0055] According to the present disclosure, since the terminal arm 10 of the industrial robot 1 is automatically operated, the measurement process is uninterrupted. Furthermore, no human intervention is required. In this way, measurement results can be obtained more quickly and measurement efficiency can be greatly improved.

[0056] Figure 8 1 is a diagram illustrating a method 900 for automatically measuring backlash of a gear 400 according to the present disclosure. Figure 4 , gear 400 is coupled between input shaft 401 and output shaft 402, input shaft 401 is coupled to motor 600, and output shaft 402 is coupled to actuator 500. At block 902, output shaft 402 is fixed. In some exemplary embodiments, the fixation can be achieved with the aid of the fixing platform 3 discussed above. At block 904, motor 600 is caused to provide torque to input shaft 401 to allow gear 400 to rotate an angle under the torque. At block 906, the torque and degree of rotation of gear 400 are obtained. At block 908, the backlash of gear 400 is determined based on the torque and degree of rotation.

[0057] According to the exemplary embodiment, the output terminal is fixed by the fixture 2, and the motor torque change can be used as the input terminal. In this case, the controller software algorithm controls the motor rotation and collects, calculates, analyzes and processes data in real time. The entire automatic process eliminates human error, saves time and energy in setting up the test environment, and the test process is simple and efficient. In this way, the measurement time is greatly shortened, the process is simplified, the measurement error can be minimized, the test frequency and utilization rate can be improved, and the cost of manpower and material resources can be reduced accordingly.

[0058] In some exemplary embodiments, the method 900 can be implemented by a software algorithm designed by a robot program, and the entire process (including torque loading, test execution, data collection, calculation and analysis reporting) does not require human intervention. In this way, the testing process is simple and efficient.

[0059] Although operations are depicted in a particular order, this should not be construed as requiring that such operations be performed in the particular order shown, or in sequential order, or that all illustrated operations be performed, in order to achieve the desired results. In certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although the above discussion includes several specific implementation details, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments.

[0060] Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A fixed platform (3), comprising: base(32); a fixing component (34) disposed on the substrate (32); a counterweight (36) coupled to the terminal arm (10) of the industrial robot (1); as well as A cylinder body (38) is disposed on the base plate (32) and adjacent to the fixing component (34), and the cylinder body includes: A plunger (380) is configured to move along a first direction (L1) to clamp the balance weight (36) when the balance weight (36) is coupled to the fixed component (34).

2. The fixed platform (3) according to claim 1, wherein the fixing member (34) comprises: a base portion (340) coupled to the substrate (32); a first protrusion (341) extending from the base portion (340); a second protrusion (342) extending from the base portion (340), wherein the second protrusion (342) is spaced apart from the first protrusion (341) along a second direction (L2) perpendicular to the first direction (L1) to form a gap (S) between the first protrusion (341) and the second protrusion (342).

3. The fixing platform (3) according to claim 2, wherein the plunger (380) includes a plunger face (385) facing the first protrusion (341) and the second protrusion (342), and the first protrusion (341) and the second protrusion (342) each include a protrusion face (345) facing the plunger (380), wherein the protrusion face (345) is parallel to the plunger face (385), so that when the balancing weight (36) is connected to the fixing component (34), the balancing weight (36) can be clamped between the protrusion face (345) and the plunger face (385).

4. The fixed platform (3) according to claim 2, wherein the balancing weight (36) is connected to the terminal arm (10) of the industrial robot (1) via a connecting rod (35), and wherein when the balancing weight (36) is connected to the fixed component (34), the connecting rod (35) can be accommodated in the gap (S) so that the balancing weight (36) can be supported by the first protrusion (341) and the second protrusion (342).

5. The fixed platform (3) according to any one of claims 1 to 4, wherein the plunger (380) can be actuated hydraulically, pneumatically or electrically.

6. The fixed platform (3) according to any one of claims 1 to 4, further comprising: A base (37) is coupled to the stationary body, wherein the base plate (32) is coupled to the base (37).

7. The fixed platform (3) according to any one of claims 1 to 4, further comprising: An image capture module is disposed adjacent the fixed member (34) and is configured to assist in positioning the counterweight (36) on the fixed member (34).

8. The fixed platform (3) according to claim 6, wherein the stationary body is the ground.

9. A method for automatically measuring backlash of a gear (400), the gear (400) being coupled between an input shaft (401) and an output shaft (402), the input shaft (401) being coupled to a motor (600), and the output shaft (402) being coupled to an actuator (500), the method comprising: Fixing the output shaft (402); causing the motor (600) to provide torque to the input shaft (401) to allow the gear (400) to rotate by an angle under the torque; Obtaining the torque and rotation degree of the gear (400); as well as determining the backlash of the gear (400) based on the torque and the degree of rotation, The output shaft (402) is fixed by means of a fixing platform (3) according to any one of claims 1 to 8.

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