CN219757954U - Rigidity testing device of mechanical arm joint - Google Patents
Rigidity testing device of mechanical arm joint Download PDFInfo
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Abstract
The utility model relates to a rigidity testing device of a mechanical arm joint, which comprises a testing platform, a mounting seat and a force application assembly, wherein the mounting seat is used for fixing a second end of the mechanical arm joint; the mounting seat is provided with a first position relative to the test platform; the force application component is arranged on the test platform and connected with the first end of the mechanical arm joint; when the mounting seat is at the first position; the force application assembly applies a tensile force along the radial direction of the mechanical arm joint to the first end; in the first position, the direction of the pulling force applied to the mechanical arm joint by the force application component is parallel to the end face of the first end of the mechanical arm joint. When the device is used for testing the rigidity of the joint of the mechanical arm, the operation process is simpler, the error is smaller, and the accuracy is higher.
Description
Technical Field
The utility model relates to the technical field of rigidity testing, in particular to a rigidity testing device of a mechanical arm joint.
Background
With the continuous development of artificial intelligence technology and robotics, robots replace or assist humans in more and more fields in order to better accomplish work. The mechanical arm belongs to one type of robot, and is widely applied to the fields of medical equipment, industrial assembly and the like due to the unique operation flexibility of the mechanical arm. In the design and research and development process of the mechanical arm, the rigidity of the mechanical arm is an extremely important index of the working characteristics of the whole mechanical arm, and the rigidity of the mechanical arm is determined by the rigidity of each joint, and the rigidity of each joint of the mechanical arm in 6 directions is determined. When the rigidity test is carried out on the mechanical arm, most of the existing test devices are complex in structure, and almost all load is applied to the tail end of the mechanical arm, so that the rigidity of the whole mechanical arm can be tested, and the rigidity results of 6 directions of each joint cannot be obtained. Therefore, when the stiffness test is performed on the mechanical arm, the operation is complicated and complicated, and the error of the test result is large.
Disclosure of Invention
Based on the above, it is necessary to provide a stiffness testing device for a joint of a mechanical arm, which aims at the technical problems that the testing device is complex and the error of the testing result is large when the stiffness testing is performed on the mechanical arm.
A stiffness testing device of a robotic arm joint for testing the stiffness of the robotic arm joint, wherein the robotic arm joint includes a first end and a second end disposed axially opposite along the robotic arm joint, the stiffness testing device of the robotic arm joint comprising:
a test platform;
the mounting seat is used for fixing the second end of the mechanical arm joint through a cantilever; the relative positions of the mounting seat and the test platform are adjustable, and the mounting seat has a first position relative to the test platform;
the force application assembly is arranged on the test platform and connected with the first end of the mechanical arm joint; when the mounting seat is at the first position; the force application component is used for applying a tensile force along a first direction to the first end, and the first direction is the radial direction of the mechanical arm joint;
and in the first position, the direction of the pulling force applied to the mechanical arm joint by the force application assembly is parallel to the end face of the first end of the mechanical arm joint.
When the stiffness test device of the mechanical arm joint is used for testing the stiffness of the single mechanical arm joint, the second end cantilever of the single mechanical arm joint is fixed on the mounting seat, then the position of the mounting seat relative to the test platform is adjusted to the first position, and the force application assembly applies the tensile force along the radial direction of the mechanical arm joint to the first end, so that the corresponding experimental test is carried out on the tensile stiffness and the torsional stiffness of the mechanical arm joint in the radial direction and the torsional stiffness of the mechanical arm joint in the axial direction, and the operation process of the whole test process is simpler. In addition, the rigidity testing device of the mechanical arm joint directly calculates the tensile rigidity and the torsional rigidity of the single mechanical arm joint in the radial direction and the torsional rigidity in the axial direction according to the measured tensile force related to the single mechanical arm joint, so that the tensile rigidity and the torsional rigidity of the single mechanical arm joint do not need to be calculated and solved by establishing an additional mathematical model, the calculation process is simpler, the error is smaller, the accuracy is higher, and the device is beneficial to the precise and efficient design and research and development of the mechanical arm.
Drawings
Fig. 1 is a front connection view of a first fixed pulley, a first pull rope, a first balancing weight, a first reversing wheel and a mechanical arm joint in a first state in a force application assembly when an installation seat in a mechanical arm joint rigidity testing device provided by an embodiment of the application is in a first position;
FIG. 2 is an enlarged view of a portion at A in FIG. 1;
fig. 3 is a top view of a connection between a first fixed pulley, a first pull rope, a first balancing weight, a first reversing wheel and a mechanical arm joint in a first state in a force application assembly when a mounting seat in the stiffness testing device of the mechanical arm joint shown in fig. 1 is in a first position;
FIG. 4 is a partial enlarged view at B in FIG. 3;
fig. 5 is a front connection view of a first fixed pulley, a first pull rope, a first balancing weight, a first reversing wheel and a mechanical arm joint in a second state when an installation seat in a stiffness test device of the mechanical arm joint provided by an embodiment of the application is at a first position;
fig. 6 is a top view of the connection between the first fixed pulley, the first pull rope, the first balancing weight, the first reversing wheel and the mechanical arm joint in the second state in the force application assembly when the mounting seat in the stiffness testing device of the mechanical arm joint shown in fig. 5 is in the first position;
FIG. 7 is a partial enlarged view at C in FIG. 6;
fig. 8 is a front connection view of a second fixed pulley, a second pull rope, a second balancing weight, a second reversing wheel and a mechanical arm joint in a third state in a force application assembly when an installation seat in the mechanical arm joint rigidity testing device provided by an embodiment of the application is in a first position;
Fig. 9 is a partial enlarged view at D in fig. 8;
fig. 10 is a top view of the connection of the second fixed pulley, the second pull rope, the second balancing weight, and the second reversing wheel in the force application assembly with the mechanical arm joint in a third state when the mounting seat in the stiffness testing device of the mechanical arm joint shown in fig. 8 is in the first position;
fig. 11 is a front view of a connection between a third fixed pulley, a third pull rope, a third balancing weight, a third reversing wheel, a measurement assembly and a mechanical arm joint in a fourth state when an installation seat in the mechanical arm joint rigidity test device provided by an embodiment of the present application is at a second position;
FIG. 12 is an enlarged view of a portion at E in FIG. 11;
fig. 13 is a front view of a connection of a third fixed pulley, a third pull rope, a third balancing weight, a third reversing wheel and the mechanical arm joint in a fourth state in the force application assembly when the mounting seat in the stiffness testing device of the mechanical arm joint shown in fig. 11 is in a second position;
fig. 14 is a top view illustrating connection of a third fixed pulley, a third pull rope, a third counterweight block, and a third reversing wheel in the force application assembly with the mechanical arm joint in a fourth state when the mounting seat in the stiffness testing device of the mechanical arm joint shown in fig. 13 is in the second position.
Reference numerals: 100-a test platform; 200-mounting seats; 300-force application assembly; 311-a first fixed pulley; 312-first pull rope; 313-a first weight; 314—a first reversing wheel; 321-a second fixed pulley; 322-a second pull cord; 323-a second balancing weight; 324-a second reversing wheel; 331-a third fixed pulley; 332-a third pull rope; 333-a third balancing weight; 334-third reversing wheel; 340-supporting rods; 400-measuring assembly; 500-connectors; 600-mechanical arm joints; 610-a first end; 620-a second end; 700-force loading disc; 710—a first test point; 720-second test point.
Detailed Description
In order that the above objects, features and advantages of the utility model will be readily understood, a more particular description of the utility model will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present utility model. The present utility model may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the utility model, whereby the utility model is not limited to the specific embodiments disclosed below.
In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.
In the present utility model, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.
It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.
Referring to fig. 1, 3, 5, 6, 8 and 10, fig. 1 is a front view illustrating connection between a first fixed pulley 311, a first pull rope 312, a first balancing weight 313, a first reversing wheel 314 and a mechanical arm joint 600 in a first state when a mounting seat 200 in a mechanical arm joint stiffness testing device according to an embodiment of the present application is at a first position; fig. 3 is a top view illustrating connection of the first fixed pulley 311, the first pull rope 312, the first balancing weight 313, the first reversing wheel 314 and the mechanical arm joint 600 in the first state in the force application assembly 300 when the mounting base 200 in the stiffness testing device of the mechanical arm joint shown in fig. 1 is in the first position; fig. 5 is a front view illustrating connection of the first fixed pulley 311, the first pull rope 312, the first balancing weight 313, the first reversing wheel 314 and the mechanical arm joint 600 in the second state in the force application assembly 300 when the mounting seat 200 in the mechanical arm joint stiffness testing device provided by the embodiment of the application is at the first position; fig. 6 is a top view illustrating connection of the first fixed pulley 311, the first pull rope 312, the first balancing weight 313, and the first reversing wheel 314 in the force application assembly 300 and the mechanical arm joint 600 in a second state when the mounting base 200 in the stiffness testing device of the mechanical arm joint shown in fig. 5 is in the first position; fig. 8 is a front view illustrating connection of the second fixed pulley 321, the second pull rope 322, the second balancing weight 323, and the second reversing wheel 324 in the force application assembly 300 with the mechanical arm joint 600 in a third state when the mounting seat 200 in the mechanical arm joint stiffness testing device provided by the embodiment of the application is at the first position; fig. 10 is a top view illustrating the connection between the second fixed pulley 321, the second pull rope 322, the second balancing weight 323, and the second reversing wheel 324 of the force application assembly 300 and the mechanical arm joint 600 in a third state when the mounting base 200 of the mechanical arm joint stiffness testing device shown in fig. 8 is at the first position.
The stiffness testing device of the mechanical arm joint according to an embodiment of the present utility model is configured to test the stiffness of the mechanical arm joint 600, where the mechanical arm joint 600 includes a first end 610 and a second end 620 that are disposed opposite to each other along an axial direction of the mechanical arm joint 600, and specifically, the axial direction of the mechanical arm joint 600 is the xx' direction in fig. 11. The stiffness testing device of the mechanical arm joint comprises a testing platform 100, a mounting seat 200 and a force application assembly 300. The mounting base 200 is used for cantilever-fixing the second end 620 of the mechanical arm joint 600; the relative positions of the mounting seat 200 and the test platform 100 are adjustable, and the mounting seat 200 has a first position relative to the test platform 100; the force application assembly 300 is mounted on the test platform 100 and is connected to the first end 610 of the mechanical arm joint 600; when the mounting base 200 is in the first position; the force application assembly 300 is configured to apply a tensile force to the first end 610 in a first direction, which is a radial direction of the mechanical arm joint 600, specifically, a xx' direction in fig. 1 when the mount 200 is in the first position; in the first position, the direction of the pulling force applied by the force application assembly 300 to the mechanical arm joint 600 is parallel to the end surface of the first end 610 of the mechanical arm joint 600.
It should be noted that, when the stiffness test device of the mechanical arm joint performs the stiffness test on the single mechanical arm joint 600, the tensile stiffness and the torsional stiffness of the mechanical arm joint 600 along the axial direction thereof can be calculated, and the tensile stiffness and the torsional stiffness of the mechanical arm joint 600 along the radial direction thereof can also be calculated.
Specifically, when the stiffness test device of the mechanical arm joint is used for testing the stiffness of the single mechanical arm joint 600, the second end 620 of the single mechanical arm joint 600 is cantilever-fixed on the mounting seat 200, then the position of the mounting seat 200 relative to the test platform 100 is adjusted to the first position, and the force application assembly 300 applies a tensile force along the radial direction of the mechanical arm joint 600 to the first end 610, so that corresponding experimental tests are performed on the tensile stiffness and the torsional stiffness of the mechanical arm joint 600 in the radial direction and the torsional stiffness of the mechanical arm joint in the axial direction, and the operation process of the whole test process is simpler. In addition, the rigidity testing device of the mechanical arm joint directly calculates the tensile rigidity and the torsional rigidity of the single mechanical arm joint 600 in the radial direction and the torsional rigidity in the axial direction according to the measured tensile force related to the single mechanical arm joint 600, so that an additional mathematical model is not required to be established to calculate and solve the tensile rigidity and the torsional rigidity of the single mechanical arm joint 600, the calculation process is simpler, the error is smaller, the accuracy is higher, and the mechanical arm rigidity testing device is beneficial to precise and efficient design and research and development of mechanical arms.
Since the mechanical arm joint 600 tested by the present apparatus is cylindrical, the tensile rigidity and the torsional rigidity in the radial direction in the xx ' direction in fig. 1 are the same as those in the zz ' direction in fig. 1, and the tensile rigidity and the torsional rigidity in the xx ' direction are taken as examples for the following description. Of course, if the mechanical arm joint 600 is not cylindrical, it is also possible to measure the radial tensile stiffness and torsional stiffness in the zz 'direction after rotating the mechanical arm joint 600 by 90 ° after measuring the radial tensile stiffness and torsional stiffness in the xx' direction.
In the first position, the direction of the pulling force applied to the mechanical arm joint 600 by the force application assembly 300 may be parallel to the end surface of the first end 610 of the mechanical arm joint 600. For example, in fig. 3, 4 and 10, the vertical plane in which the direction of the pulling force applied to the mechanical arm joint 600 by the force application assembly 300 is located is spaced apart from the end face of the first end 610 of the mechanical arm joint 600 by a distance, but the distance is smaller, so that the direction of the pulling force applied to the mechanical arm joint 600 by the force application assembly 300 can be considered to be in the same vertical plane as the end face of the first end 610 of the mechanical arm joint 600. Alternatively, in fig. 5 and 6, the vertical plane in which the direction of the pulling force applied by the force application assembly 300 to the mechanical arm joint 600 is located has a certain preset distance from the end face of the first end 610 of the mechanical arm joint 600, but the preset distance is larger, so that the two planes are parallel.
Referring to fig. 11 and fig. 13-14, fig. 11 is a front view illustrating connection of the third fixed pulley 331, the third pull rope 332, the third balancing weight 333, the third reversing wheel 334, and the measuring assembly 400 with the mechanical arm joint 600 in a fourth state when the mounting seat 200 in the mechanical arm joint stiffness testing device provided by an embodiment of the present application is at the second position; fig. 13 is a front view showing the connection of the third fixed pulley 331, the third pull rope 332, the third counterweight 333, and the third reversing wheel 334 in the force application assembly 300 and the mechanical arm joint 600 in a fourth state when the mounting seat 200 in the stiffness testing device of the mechanical arm joint shown in fig. 11 is in the second position; fig. 14 is a top view showing the connection of the third fixed pulley 331, the third pull rope 332, the third counterweight 333, and the third reversing wheel 334 in the force application assembly 300 with the mechanical arm joint 600 in the fourth state when the mounting base 200 in the stiffness testing device for the mechanical arm joint shown in fig. 13 is in the second position.
The mounting seat 200 of the stiffness testing device of the mechanical arm joint provided by the embodiment of the application has a second position relative to the testing platform 100; the force application assembly 300 is configured to apply a tensile force to the first end 610 in a second direction along the axial direction of the mechanical arm joint 600 when the mount 200 is in the second position, and specifically, in the xx' direction in fig. 11 when the mount 200 is in the second position; in the second position, the direction of the pulling force applied by the force application assembly 300 to the robotic arm joint 600 is disposed at an angle to the end face of the first end 610 of the robotic arm joint 600. After the corresponding experimental tests are performed on the tensile stiffness and the torsional stiffness in the radial direction and the torsional stiffness in the axial direction of the mechanical arm joint, the position of the mounting seat 200 relative to the test platform 100 is adjusted to the second position, and the force application assembly 300 applies a tensile force along the axial direction of the mechanical arm joint 600 to the first end 610, so that the corresponding experimental test is performed on the tensile stiffness in the axial direction of the mechanical arm joint 600. By changing the position of the mounting seat 200 relative to the test platform 100, the force application direction of the force application assembly 300 to the mechanical arm joint 600 is changed, and then the rigidity test of the mechanical arm joint in different directions is realized, so that the operation is simple and convenient.
It should be noted that, in the second position, the direction of the pulling force applied by the force application assembly 300 to the mechanical arm joint 600 may be disposed at an angle with respect to the end surface of the first end 610 of the mechanical arm joint 600. For example, the direction of the pulling force applied by the force application assembly 300 to the arm joint 600 is perpendicular to the end face of the first end 610 of the arm joint 600, that is, the direction of the pulling force applied by the force application assembly to the arm joint 600 is at an angle of 90 ° to the end face of the first end 610 of the arm joint 600. The direction of the pulling force applied to the arm joint 600 by the force application unit 300 may be at an angle of 85 ° or 88 ° with respect to the end surface of the first end 610 of the arm joint 600.
The following specifically describes the structure of the stiffness testing device of the mechanical arm joint. Please refer to fig. 2, 4, 7, 9 and 12. Fig. 2 shows a partial enlarged view at a in fig. 1; fig. 4 shows a partial enlarged view at B in fig. 3; FIG. 7 shows a partial enlarged view at C in FIG. 6; fig. 9 shows a partial enlarged view at D in fig. 8; fig. 12 shows a partial enlarged view at E in fig. 11.
In one embodiment, the stiffness testing device of the mechanical arm joint further comprises a mounting piece; the test platform 100 is configured with a plurality of mounting holes arranged at intervals, and the mounting member passes through the mounting seat 200 and is detachably connected with the hole wall of the mounting hole. Specifically, the mounting member may be a threaded connection member 500, and the mounting hole is a threaded connection hole. Or the mounting piece can also be a pin, and the mounting hole is a pin hole.
Referring to fig. 1, 3, 5-9, and 14, the stiffness testing apparatus for a mechanical arm joint according to an embodiment of the present application further includes a measurement assembly 400; the measuring assembly 400 is used for measuring displacement of the first end 610 along the first direction when the force application assembly 300 applies a pulling force along the first direction to the first end 610; the measuring assembly 400 is used to measure the displacement of the first end 610 in the second direction when the force application assembly 300 applies a pulling force to the first end 610 in the second direction. The tensile stiffness and torsional stiffness of the test piece to be tested can be calculated by measuring the displacement of the first end 610 along the first direction or along the second direction, and the tension applied to the first end 610 by the force application assembly 300 along the first direction and the tension along the second direction, which are measured by the measuring assembly 400.
In one specific embodiment, the measuring assembly 400 is a dial gauge, and the displacement of the first end 610 in the first direction or in the second direction is measured by mounting the dial gauge on the test platform 100. Specifically, the dial indicator is adsorbed on the test platform 100 prepared by cast iron through the magnetic absorption meter seat, and because the rotation angle of the mechanical arm joint 600 in the rigidity test is very small, the arc length and the chord length of the mechanical arm joint 600 rotated in the test process are considered to be equal, namely, the linear displacement is equivalent to the arc length, while the part contacted with the test point of the dial indicator is a square block, which can be contacted with the measuring rod of the dial indicator, so that the displacement of the first end 610 along the first direction or along the second direction is measured by the dial indicator.
In other embodiments, the measuring assembly 400 may be a laser tracker, an encoder, a laser range finder, or the like, which is not particularly limited.
Referring to fig. 5 to fig. 7, the stiffness testing apparatus for a mechanical arm joint according to an embodiment of the present application further includes a connecting member 500, wherein in a first position, the connecting member 500 is detachably connected to the first end 610, and when the connecting member 500 is connected to the first end 610, a predetermined distance is provided between an end surface of the connecting member 500 facing away from the first end 610 and the first end 610.
Referring to fig. 1-4, in the first position, the force application assembly 300 is configured to apply a first tensile force in a first direction to the first end 610 when the connecting member 500 is disconnected from the first end 610; or referring to fig. 5-7, the force application assembly 300 is configured to apply a second tensile force in a first direction to the connector 500 when the connector 500 is connected to the first end 610; the measuring assembly 400 is configured to detect a first displacement of the first end 610 in a first direction when subjected to a first tensile force; or for detecting a second displacement of the connector 500 in the first direction when subjected to a second tensile force. The tensile stiffness and torsional stiffness of the tested mechanical arm joint 600 in the first direction are obtained by the first tension and the first displacement, and the second tension and the second displacement. In one particular embodiment, the connector 500 is a sleeve that is threadably coupled to the first end 610.
The stiffness testing device for a mechanical arm joint according to an embodiment of the present application further includes a force loading disc 700, please refer to fig. 1-4, wherein in the first position, the force loading disc 700 is sleeved on the first end 610, and please refer to fig. 5-7, the force loading disc 700 is sleeved on the connecting piece 500; the end surface of the force loading disc 700 comprises a first test point 710, and a connecting line of the first test point 710 and the center p of the end surface of the force loading disc 700 is parallel to a preset plane. It should be noted that the predetermined plane is any plane parallel to the plane of the mounting seat 200 on the test platform 100, that is, the horizontal plane indicated by the dashed line in fig. 2.
The force application assembly 300 includes a first pulley assembly including a first fixed pulley 311, a first pull cord 312, and a first counterweight 313; one end of the first pull rope 312 is connected with the first test point 710, and the other end of the first pull rope 312 bypasses the first fixed pulley 311 and is connected with the first balancing weight 313; the first balancing weight 313 applies a first tensile force in a first direction to the first end 610 or a second tensile force in the first direction to the connection 500 through the force loading plate 700. Through the cooperation of the first fixed pulley 311, the first pull rope 312 and the first balancing weight 313, the gravity of the first balancing weight 313 can be applied to the first end 610 or the connecting piece 500 through the force loading disc 700 under the transmission action of the first pull rope 312 and the first fixed pulley 311. The tensile stiffness and torsional stiffness of the tested robotic arm joint 600 in the xx' direction in fig. 1 are then calculated from the magnitude of the pulling force and the magnitude of the measured displacement.
The specific calculation process is as follows:
referring to fig. 1-4, when the connection member 500 is not connected to the first end 610, the force application assembly 300 applies a first tensile force along the xx 'direction to the first end 610, and the state that the measurement assembly 400 detects a first displacement along the xx' direction when the first end 610 receives the first tensile force is defined as a first state. Repeating the steps of obtaining the values of the first tension and the first displacement for a plurality of times under the first state, wherein the values of the first tension in each repetition process are different. During each repetition, the first end 610 of the arm joint 600 is subjected to a first tensile force F 1i The conditions are satisfied:
F 1i ＝F 11 +(i-1)F 5
wherein i is the number of repeated operations; f (F) 5 Is a preset value.
Will y 1 Is arranged as the mechanical arm joint 600 per increment unit F 5 Magnitude load, average value of first displacement change, y 1i Is arranged that in each repetition process, the mechanical arm joint 600 is increased by a unit F 5 The magnitude of the load, the magnitude of the first displacement change, y 1 For y in multiple repetition 1i And further determining the average value of the first displacement change every unit load increase of the test piece to be tested.
Will k 1 Set as tensile stiffness, k, of the robotic arm joint 600 in the xx' direction 2 Is set to the torsional rigidity of the robot arm joint 600 in the xx' direction; l (L) 1 Is the length of the distance between the first end 610 and the second end 620 of the robotic arm joint 600; then F 5 The conditions are satisfied:
5-7, the force application assembly 300 applies a second pulling force in the xx' direction to the connector 500 when the connector 500 is connected to the first end 610; the state in which the measuring assembly 400 detects the second displacement in the xx' direction when the connecting member 500 receives the second tensile force is defined as a second state. Repeating the steps of obtaining the values of the second pulling force and the second displacement for a plurality of times under the second state, wherein the values of the second pulling force in each repetition process are different. During each repetition, the first end 610 of the mechanical arm joint 600 receives a second tensile force F 2i The conditions are satisfied:
F 2i ＝F 21 +(i-1)F 5
wherein i is the number of repeated operations; f (F) 5 Is a preset value.
Will y 2 Is arranged as the mechanical arm joint 600 per increment unit F 5 Magnitude load, average magnitude of second displacement change, y 2i Is arranged in each repeated process, is provided with a mechanical armPer unit F of articulation 600 5 Magnitude of load, second displacement change, y 2 For y in multiple repetition 2i And further determining the average value of the second displacement change every time the load of the unit size is increased to the test piece to be tested.
L 2 Is set to a distance length between the second end 620 of the robot arm joint 600 and an end surface of the connecting member 500 facing away from the first end 610; then F 5 The conditions are also satisfied:
by combining the two relational expressions, it is possible to obtain:
and further can solve the tensile rigidity k of the mechanical arm joint 600 along the xx' direction 1 Torsional stiffness k of the robotic arm joint 600 in the xx' direction 2 。
In one specific embodiment, when the step of obtaining the values of the first tension and the first displacement in the first state is repeated for a plurality of times, the first balancing weight 313 is applied from 0kg to 10kg with a gradient of 1kg, and after each application of the first balancing weight 313, the first balancing weight 313 stays for 10s, and after the indication of the component 400 to be measured is stable, the corresponding weight of the first balancing weight 313 and the indication of the measuring component 400 are read and recorded. When the steps of obtaining the values of the second tension and the second displacement in the second state are repeated for a plurality of times, the first balancing weight 313 is applied from 0kg to 10kg with a gradient of 1kg, and after the first balancing weight 313 is applied each time, the first balancing weight 313 stays for 10s, and after the indication of the component 400 to be measured is stable, the weight of the corresponding first balancing weight 313 and the measuring component are read and recorded400, thus F 5 The value is 10N. Of course, in other embodiments, when the size of the robotic arm joint 600 is larger, F 5 The value may be a larger value, for example, 20N, 30N, 100N, or the like, and is not particularly limited.
In the above analysis, it should be noted that, in the first state, the arm joint 600 is set to receive the tensile force F along the xx' direction 5 When the deformation of the pure radial stretching is y 11 Deformation y of pure radial torque in xx' direction 12 Then there is:
y 11 +y 12 ＝y 1
thus, it can be derived from the three formulas above:
similarly, y in the second state 2 The analysis of the derivation process of (a) is the same as the analysis of the first state. In the second state, y 21 Is configured such that the robotic arm joint 600 is subjected to a purely radial tensile force F in the xx' direction 5 Deformation at the time of y 22 Is set as the deformation amount, L, of the mechanical arm joint 600 when subjected to pure radial torque along the xx' direction 2 A distance between the mount 200 and an end surface of the connector 500 facing away from the first end, i.e., a distance of the second end 620 from the first end relative to the force loading plate 700; y is 2 Per increment of unit F for the robotic arm joint 600 5 Magnitude load, average value of second displacement variation; then there is:
y 21 +y 22 ＝y 2
thus, it can be derived from the three formulas above:
in one specific embodiment, the connector 500 is screwed to the first end 610 of the arm joint 600, and the material of the connector 500 may be carbon steel or stainless steel, so that the connector is relatively rigid. Specifically, the stiffness of the mechanical arm joint 600 is k 5 The stiffness of the connection 500 is k 6 When the connecting member 500 is connected to the first end 610 of the mechanical arm joint 600, the stiffness of the combination formed by the two is k, and the three stiffness satisfy the condition:
it can be seen that when the stiffness k of the connector 500 itself 6 At high levels, the stiffness k of the link 500 is compared to the stiffness k5 of the robotic arm joint 600 6 It can be considered to be positive, so that the total stiffness k after the attachment of the link 500 is almost the same as the stiffness k of the arm joint 600 5 Equivalently, the addition of the connector 500 may result in substantially negligible error in the stiffness test of the robotic arm joint 600.
It should be noted that, the device extends the mechanical arm joint 600 through the connecting piece 500, pulls the first end 610 of the mechanical arm joint 600 with the same force before and after extension, and finally obtains the tensile stiffness and torsional stiffness of the mechanical arm joint 600 in the xx' direction in fig. 1 through difference calculation, so that the whole testing device constructs a pure couple detection environment which is easier to realize, and the testing device is simpler, and the testing process and the calculating process are simpler and more convenient.
Referring to fig. 1 and 2, in the stiffness testing device for a mechanical arm joint according to an embodiment of the present application, an included angle θ between a first pull rope 312 and a predetermined plane is located between a first fixed pulley 311 and a first test point 710 1 The conditions are satisfied: theta is 0 to or less 1 Less than or equal to 5 degrees. By bringing the angle theta 1 The value range of (2) is set to be greater than or equal to 0 and less than or equal to 5 °, so that the angle between the direction of the pulling force applied by the first pull rope 312 to the first end 610 or the connecting piece 500 and the preset plane, that is, the horizontal plane, is smaller, and further, the component force of the first pulling force and the second pulling force along the vertical plane is smaller, and the error of the finally calculated tensile stiffness and torsional stiffness of the mechanical arm joint 600 along the first direction is smaller.
Specifically, when the included angle theta 1 When the value 0 is taken, that is, the direction of the pulling force applied by the first pulling rope 312 to the first end 610 or the connecting piece 500 is parallel to the preset plane, the forces of the first pulling force and the second pulling force along the xx 'direction in fig. 1 are the actual gravity values of the first balancing weight 313, so that the error of the finally calculated tensile stiffness and torsional stiffness of the mechanical arm joint 600 along the xx' direction in fig. 1 is very small.
While when the included angle theta 1 When the value of (a) is 5 °, that is, the included angle between the direction of the pulling force applied by the first pulling rope 312 to the first end 610 or the connecting piece 500 and the preset plane is smaller, the forces of the first pulling force and the second pulling force along the xx 'direction in fig. 1 are the actual gravity value of the first balancing weight 313 multiplied by cos5 °, and cos5 ° is equal to 0.996, so that the finally calculated errors of the tensile stiffness and the torsional stiffness of the mechanical arm joint 600 along the xx' direction in fig. 1 are smaller from the actual values. Of course in other embodiments, the angle θ 1 The value of (2) or 3 may be used, and is not particularly limited.
It should be noted that when the included angle θ 1 When the value of (2) is 0, it is the best embodiment, but it is difficult to adjust the included angle theta due to the manufacturing errors of the components 1 The value of (2) is always 0, so that the included angle theta 1 The installation requirement of the device in the process of testing the rigidity of the mechanical arm joint 600 can be met within a range of 0-5 degrees, the operation can greatly reduce the debugging time in the whole rigidity test experiment process, and the rigidity test process is quickened.
Referring to fig. 1, 3, 5 and 6, a force application assembly 300 of a stiffness testing device for a mechanical arm joint according to an embodiment of the present application includes a support bar 340, the support bar 340 is mounted on a testing platform 100, and a first fixed pulley 311 is detachably connected to the support bar 340, so that a height of the first fixed pulley 311 relative to the testing platform 100 is adjustable, so as to conveniently adjust an included angle θ between a first pull rope 312 and a preset plane between the first fixed pulley 311 and a first testing point 710 1 Is of a size of (a) and (b).
Referring to fig. 1, 3, 5 and 6, the first pulley assembly of the stiffness testing apparatus for a mechanical arm joint according to an embodiment of the present application further includes a first reversing wheel 314, where the first reversing wheel 314 is spaced from the first fixed pulley 311, and a distance between the first reversing wheel 314 and the testing platform 100 is greater than a height of the first fixed pulley 311 relative to the testing platform 100. One end of the first pull rope 312 is wound to the first fixed pulley 311 and then wound to the first reversing wheel 314, and finally connected with the first balancing weight 313. Through setting up first switching-over wheel 314 for can change the direction of first stay 312 and not change the size of power, make things convenient for the change of the size of first balancing weight 313, and then make things convenient for the change of first pulling force and second pulling force. It should be noted that the number of the first reversing wheels 314 is not limited, and may be one or more of those shown in fig. 1, 3, 5 and 6.
Referring to fig. 8 to fig. 10, the force application assembly 300 of the stiffness testing device for a mechanical arm joint according to an embodiment of the present application further includes two sets of second pulley assemblies, where when the mounting seat 200 is at the first position, the two sets of second pulley assemblies are respectively disposed on two radial sides of the end face of the first end 610 of the mechanical arm joint 600; the force loading disc 700 is sleeved and mounted on the first end 610, and the end surface of the force loading disc 700 comprises two second test points 720, wherein the two second test points 720 are respectively arranged at two sides of the center p of the end surface of the force loading disc 700; and the connection line between each second test point 720 and the center p of the end face of the force loading disc 700 is perpendicular to the preset plane; each group of second pulley assembly comprises a second fixed pulley 321, a second stay 322 and a second balancing weight 323; one end of a second stay rope 322 in the two groups of second pulley assemblies is respectively connected with one second test point 720, and the other end of the second stay rope bypasses a second fixed pulley 321 in the corresponding second pulley assembly and is connected with a second balancing weight 323; when the second end 620 is cantilever-fixed to the mounting base 200, the two second balancing weights 323 apply third tensile forces opposite to the first direction to the first end 610 through the force loading disc 700 respectively; the measuring assembly 400 is used for measuring a third displacement of the first end 610 in the first direction when the two second balancing weights 323 apply a third tensile force to the first end 610 in the opposite direction of the first direction through the force loading plate 700, respectively.
Under the common cooperation of the second fixed pulleys 321, the second pull ropes 322 and the second balancing weights 323, the gravity of the two second balancing weights 323 can be applied to two tensile forces at the upper end and the lower end of the first end 610 through the force loading disc 700 under the transmission action of the second pull ropes 322 and the second fixed pulleys 321, one of the two tensile forces is leftwards and rightwards along the xx' direction in fig. 8, and the torsional rigidity of the mechanical arm joint 600 along the axis direction of the mechanical arm joint is calculated through the third tensile force and the third displacement.
The specific calculation process is as follows:
referring to fig. 8 to 10, when the connection member 500 is not connected to the first end 610, the two second balancing weights 323 apply a third tensile force along the first direction to the first end 610 through the force loading plate 700, and the state that the measuring assembly 400 measures a third displacement of the first end 610 along the first direction is defined as a third state. And repeatedly obtaining the third tensile force and the third displacement to obtain the numerical value in the third state, wherein the numerical value of the third tensile force in each repeated process is different. During each repetition, the first end 610 of the arm joint 600 is subjected to a third tensile force F 3i The conditions are satisfied:
F 3i ＝F 31 +(i-1)F 6 ；
Wherein,,i is the number of repetitions; f (F) 6 Is a preset value.
Will y 3 Is arranged as the mechanical arm joint 600 per increment unit F 6 Magnitude load, average value of third displacement change, y 3i Is arranged that in each repetition process, the mechanical arm joint 600 is increased by a unit F 6 Magnitude of load, value of third displacement change, y 3 For y in multiple repetition 3i And further determining the average value of the third displacement change every unit load of the test piece to be tested.
Will k 3 Is provided as torsional rigidity of the mechanical arm joint 600 in its own axis direction; r is set to be the distance from the second test point 720 on the force loading disc 700 to the center p of the end face of the force loading disc 700; then F 6 The conditions are satisfied:
further, the torsional rigidity k of the mechanical arm joint 600 along the axis direction thereof can be solved by the above formula 3 。
In one specific embodiment, when the step of obtaining the values of the third tensile force and the third displacement in the third state is repeated for a plurality of times, the second balancing weight 323 is applied from 0kg to 10kg with a gradient of 1kg, and after each application of the second balancing weight 323, the second balancing weight 323 stays for 10s, and after the indication of the component 400 to be measured is stable, the weight of the corresponding second balancing weight 323 and the indication of the measuring component 400 are read and recorded. Thus F 6 The value is 10N. It is in combination with F 5 The values of the values are the same, and the operation is convenient. Of course, in other embodiments, when the size of the robotic arm joint 600 is larger, F 6 The value may be a larger value, for example, 20N, 30N, 100N, or the like, and is not particularly limited.
Referring to fig. 9, in the stiffness testing device of the mechanical arm joint according to the embodiment of the present application, a second pull rope 322 between a second fixed pulley 321 and a second test point 720 in each set of second pulley assemblies is located between the second pull rope and a predetermined planeIncluded angle theta of (2) 2 The conditions are satisfied: theta is 0 to or less 2 Less than or equal to 5 degrees. By bringing the angle theta 2 The value range of (2) is set to be greater than or equal to 0 and less than or equal to 5 °, so that the angle between the third pulling force direction applied by the second pulling rope 322 to the first end 610 and the preset plane, that is, the horizontal plane is smaller, the component force of the third pulling force along the vertical plane is smaller, and the error of the torsional rigidity of the finally calculated mechanical arm joint 600 along the axis direction thereof is smaller.
In one particular embodiment, the angle θ 2 The value of (1) is 0, that is, the direction of the third pulling force applied by the second pulling rope 322 to the first end 610 is parallel to the preset plane, and the force of the third pulling force along the xx' direction in fig. 1 is the actual gravity value of the first balancing weight 313, so that the error of the finally calculated torsional rigidity of the mechanical arm joint 600 along the axis direction thereof is very small.
In another specific embodiment thereof, the angle θ 2 The value of (1) is 5 °, that is, the included angle between the direction of the third pulling force applied by the second pulling rope 322 to the first end 610 and the preset plane is smaller, and at this time, the force of the third pulling force along the xx' direction in fig. 1 is the actual gravity value of the first balancing weight 313 multiplied by cos5 °, and cos5 ° is equal to 0.996, so that the error between the torsional rigidity of the finally calculated mechanical arm joint 600 along the axis direction thereof and the actual value is smaller. Of course in other embodiments, the angle θ 2 The value of (2) or 3 may be used, and is not particularly limited. It should be noted that, the predetermined plane is any plane parallel to the plane of the mounting base 200 on the test platform 100, that is, the horizontal plane indicated by the dashed line in fig. 9.
It should be noted that when the included angle θ 2 When the value of (2) is 0, it is the best embodiment, but it is difficult to adjust the included angle theta due to the manufacturing errors of the components 2 The value of (2) is always 0, so that the included angle theta 2 The installation requirement of the device in the process of testing the rigidity of the mechanical arm joint 600 can be met within a range of 0-5 degrees, the operation can greatly reduce the debugging time in the whole rigidity test experiment process, and the rigidity test process is quickened.
Referring to fig. 9, in the stiffness testing apparatus of a mechanical arm joint according to an embodiment of the present application, an included angle θ between the second pull ropes 322 in the two sets of second pulley assemblies 3 The conditions are satisfied: theta is 0 to or less 3 Less than or equal to 5 degrees. By bringing the angle theta 3 The value range of (2) is set to be greater than or equal to 0 and less than or equal to 5 °, so that the angle between the two directions of the third pulling forces applied by the two second pulling ropes 322 to the first end 610 is smaller, the error between the directions of the two third pulling forces is smaller, and the error of the torsional rigidity of the finally calculated mechanical arm joint 600 along the axis direction is smaller.
In one particular embodiment, the angle θ 3 The value of (1) is 0, that is, the included angle between the third pulling forces applied by the two sets of second pulling ropes 322 to the first end 610 is 0, so that the pulling forces applied to the upper end and the lower end of the first end 610 of the mechanical arm joint 600 are equal in magnitude and opposite in direction, and thus the error of the finally calculated torsional rigidity of the mechanical arm joint 600 along the axis direction thereof is very small.
In another specific embodiment thereof, the angle θ 3 The value of (2) is 5 °, that is, the included angle between the third pulling forces applied by the two sets of second pulling ropes 322 to the first end 610 is 5 °, so that the error of the directions of the two pulling forces applied to the upper and lower ends of the first end 610 of the mechanical arm joint 600 is smaller, one pulling force is cos5 ° times that of the other pulling force, and cos5 ° is equal to 0.996, so that the error between the two pulling forces is between 0.004, and therefore, the error between the torsion rigidity of the finally calculated mechanical arm joint 600 along the axis direction thereof and the actual value is smaller. Of course in other embodiments, the angle θ 3 The value of (2) or 3 may be used, and is not particularly limited.
It should be noted that when the included angle θ 3 When the value of (2) is 0, it is the best embodiment, but it is difficult to adjust the included angle theta due to the manufacturing errors of the components 3 The value of (2) is always 0, so that the included angle theta 3 The stiffness of the device can be tested on the mechanical arm joint 600 within a range of 0-5 DEGAnd according to the installation requirement, the debugging time in the whole rigidity test experiment process can be greatly reduced, and the rigidity test process is quickened.
Referring to fig. 8 and 10, the second fixed pulley 321 is detachably connected to the supporting rod 340, so that the height of the second fixed pulley 321 relative to the testing platform 100 is adjustable, thereby facilitating adjustment of the included angle θ 2 And an included angle theta 3 Is of a size of (a) and (b).
Referring to fig. 8 and 10, the second pulley assembly of the stiffness testing apparatus for a mechanical arm joint according to an embodiment of the present application further includes a second reversing wheel 324, wherein the second reversing wheel 324 is spaced apart from the second fixed pulley 321, and a distance between the second reversing wheel 324 and the testing platform 100 is greater than a height of the second fixed pulley 321 relative to the testing platform 100. One end of the second pull rope 322 is wound to the second fixed pulley 321, then wound to the second reversing wheel 324, and finally connected with the second balancing weight 323. Through setting up second switching-over wheel 324 for can change the direction of second stay cord 322 and not change the size of power, make things convenient for the change of the size of second balancing weight 323, and then make things convenient for the change of the size of third pulling force. It should be noted that the number of the second reversing wheels 324 is not limited, and may be one or more as shown in fig. 8 and 10.
Referring to fig. 11-14, the force application assembly 300 in the stiffness testing device of the mechanical arm joint according to an embodiment of the present application further includes a third pulley assembly, where the third pulley assembly includes a third fixed pulley 331, a third pull rope 332, and a third balancing weight 333; when the mounting seat 200 is at the second position, the force loading disc 700 is sleeved and mounted on the first end 610, one end of the third pull rope 332 is connected with the center p of the end face of the force loading disc 700, and the other end of the third pull rope 332 bypasses the third fixed pulley 331 and is connected with the third balancing weight 333; the third weight 333 is configured to apply a pulling force in the second direction to the first end 610 through the force loading plate 700; the measuring assembly 400 is used to detect displacement of the first end 610 in the second direction when the third weight 333 applies a pulling force in the second direction to the first end 610 through the force loading plate 700. Through the cooperation of the third fixed pulley 331, the third pull rope 332 and the third balancing weight 333, the gravity of the third balancing weight 333 can be applied to the first end 610 through the force loading disc 700 under the transmission action of the third pull rope 332 and the third fixed pulley 331. And further calculates the tensile rigidity of the tested mechanical arm joint 600 along the axis direction thereof by the tensile force and the measured displacement.
The specific calculation process is as follows:
referring to fig. 11 to 14, when the connection member 500 is not connected to the first end 610, the third weight 333 applies a tensile force in the second direction to the first end 610 through the force loading plate 700, the state in which the measurement assembly 400 detects the displacement of the first end 610 in the second direction is defined as a fourth state, and applies a tensile force in the second direction to the first end 610 is defined as a fourth tensile force, and the displacement of the first end 610 in the second direction is defined as a fourth displacement. And repeatedly obtaining the fourth pulling force and the fourth displacement to obtain the numerical value in the fourth state, wherein the numerical value of the fourth pulling force in each repeated process is different. During each repetition, the first end 610 of the arm joint 600 is subjected to a fourth tensile force F 4i The conditions are satisfied:
F 4i ＝F 41 +(i-1)F 7
wherein i is the number of repeated operations; f (F) 7 Is a preset value.
Will k 4 A tensile rigidity of the arm joint 600 in its own axis direction; y is 4 Per increment of unit F for the robotic arm joint 600 7 The average value of the fourth displacement change is F 4 The conditions are satisfied:
and the tensile rigidity k of the mechanical arm joint 600 along the axis direction thereof can be solved by the formula 4 。
In one embodiment, when the steps of obtaining the values of the fourth pulling force and the fourth displacement in the fourth state are repeated a plurality of times, the third balancing weight 333 is applied from 0kg with a gradient of 1kgTo 10kg and after each application of the third balancing weight 333, the rest is performed for 10s, and after the indication of the component 400 to be measured is stable, the weight of the corresponding third balancing weight 333 and the indication of the measuring component 400 are read and recorded. Thus F 7 The value is 10N. It is in combination with F 5 The values of the values are the same, and the operation is convenient. Of course, in other embodiments, F 7 The values may be 20N, 30N, etc., and are not particularly limited.
Referring to fig. 12, an included angle θ between the third pull rope 332 and the predetermined plane is formed between the third fixed pulley 331 and the center p of the end face of the first end 610 4 The conditions are satisfied: theta is 0 to or less 4 Less than or equal to 5 degrees. By bringing the angle theta 4 The value range of (2) is set to be greater than or equal to 0 and less than or equal to 5 °, so that the pulling force applied by the third pull rope 332 to the first end 610 along the second direction is smaller than the preset plane, that is, the angle between the axial direction of the mechanical arm joint 600 and the horizontal plane, applied by the third pull rope 332, is smaller, and further, the component force applied to the first end 610 along the pulling force direction along the vertical plane along the second direction is smaller, and finally, the error of the calculated tensile rigidity of the mechanical arm joint 600 along the axis direction thereof is smaller. It should be noted that the predetermined plane is any plane parallel to the plane of the mounting seat 200 on the test platform 100, that is, the horizontal plane indicated by the dashed line in fig. 12.
In one particular embodiment, the angle θ 4 The value of (1) is 0, that is, the direction of the pulling force applied by the third pulling rope 332 to the first end 610 along the second direction is parallel to the preset plane, and the force applied by the pulling force applied to the first end 610 along the second direction along the xx' direction in fig. 11 is the actual gravity value of the third balancing weight 333, so that the error of the finally calculated tensile stiffness of the mechanical arm joint 600 along the axis direction thereof is very small.
In another specific embodiment thereof, the angle θ 4 The value of (1) is 5 °, that is, the included angle between the direction of the pulling force along the second direction applied by the third pulling rope 332 to the first end 610 and the preset plane is smaller, and the force along the xx' direction in fig. 11 applied by the pulling force along the second direction applied by the first end 610 is the actual gravity of the first balancing weight 313The value is multiplied by cos5 °, and cos5 ° is equal to 0.996, so that the error between the finally calculated tensile stiffness of the mechanical arm joint 600 along its own axis and the actual value is small. Of course in other embodiments, the angle θ 4 The value of (2) or 3 may be used, and is not particularly limited.
It should be noted that when the included angle θ 4 When the value of (2) is 0, it is the best embodiment, but it is difficult to adjust the included angle theta due to the manufacturing errors of the components 4 The value of (2) is always 0, so that the included angle theta 4 The installation requirement of the device in the process of testing the rigidity of the mechanical arm joint 600 can be met within a range of 0-5 degrees, the operation can greatly reduce the debugging time in the whole rigidity test experiment process, and the rigidity test process is quickened.
Referring to fig. 11 and 13, the third fixed pulley 331 is detachably connected to the supporting rod 340, so that the height of the third fixed pulley 331 relative to the testing platform 100 is adjustable, thereby facilitating adjustment of the included angle θ 4 Is of a size of (a) and (b).
Referring to fig. 11 and 13, the third pulley assembly of the stiffness testing apparatus for a mechanical arm joint according to an embodiment of the present application further includes a third reversing wheel 334, wherein the third reversing wheel 334 is spaced apart from the third fixed pulley 331, and a distance between the third reversing wheel 334 and the testing platform 100 is greater than a height of the third fixed pulley 331 relative to the testing platform 100. One end of the third pull rope 332 is wound to the third fixed pulley 331 and then wound to the third reversing wheel 334, and finally connected with the third balancing weight 333. By providing the third reversing wheel 334, the direction of the force of the third pull rope 332 can be changed without changing the magnitude of the force, so that the third balancing weight 333 is conveniently replaced, and the magnitude of the pulling force applied to the first end 610 along the second direction is conveniently adjusted. Note that, the number of the third reversing wheels 334 is not limited, and may be one or more as shown in fig. 11 and 13.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.
Claims (12)
1. A stiffness testing device of a robotic arm joint for testing the stiffness of a robotic arm joint (600), wherein the robotic arm joint (600) comprises a first end (610) and a second end (620) arranged axially opposite to each other along its own axis, characterized in that the stiffness testing device of a robotic arm joint comprises:
a test platform (100);
A mount (200), the mount (200) configured to cantilever secure a second end (620) of the robotic arm joint (600); the relative positions of the mounting seat (200) and the test platform (100) are adjustable, and the mounting seat (200) has a first position relative to the test platform (100);
the force application assembly (300) is arranged on the test platform (100) and is connected with the first end (610) of the mechanical arm joint (600); when the mounting seat (200) is at a first position; the force application assembly (300) is configured to apply a tensile force to the first end (610) in a first direction, the first direction being a radial direction of the robotic arm joint (600);
wherein, in the first position, the direction of the pulling force applied by the force application assembly (300) to the mechanical arm joint (600) is parallel to the end surface of the first end (610) of the mechanical arm joint (600).
2. The device for testing the stiffness of a robotic arm joint according to claim 1, wherein the mounting base (200) has a second position relative to the test platform (100);
when the mounting seat (200) is in the second position, the force application assembly (300) is used for applying a pulling force along a second direction to the first end (610), and the second direction is the axial direction of the mechanical arm joint (600);
In the second position, a pulling force applied to the mechanical arm joint (600) by the force application assembly (300) is arranged at an included angle with the end face of the first end (610) of the mechanical arm joint (600).
3. The stiffness testing apparatus of a robotic arm joint according to any one of claims 1 or 2, further comprising a mounting;
the test platform (100) is provided with a plurality of mounting holes arranged at intervals, and the mounting piece penetrates through the mounting seat (200) and is detachably connected with the hole wall of the mounting hole.
4. The device for testing the stiffness of the mechanical arm joint according to claim 2, further comprising a measuring assembly (400); -the force application assembly (300) is configured to measure displacement of the first end (610) in the first direction when a pulling force in the first direction is applied to the first end (610); the measurement assembly (400) is configured to measure displacement of the first end (610) in the second direction when the force application assembly (300) applies a pulling force to the first end (610) in the second direction.
5. The device for testing the stiffness of a robotic arm joint according to claim 4, further comprising a connector (500), wherein in the first position, the connector (500) is detachably connected to the first end (610), and wherein when the connector (500) is connected to the first end (610), a predetermined distance is provided between an end surface of the connector (500) facing away from the first end (610) and the first end (610);
In the first position, the force application assembly (300) is configured to apply a first pulling force in a first direction to the first end (610) when the connector (500) is disconnected from the first end (610); or for applying a second pulling force in the first direction to the connection member (500) when the connection member (500) is connected with the first end (610);
-the measuring assembly (400) is adapted to detect a first displacement of the first end (610) in the first direction when subjected to the first tensile force; or for detecting a second displacement of the connecting member (500) in the first direction when subjected to the second tensile force.
6. The device for testing the stiffness of a robotic arm joint according to claim 5, further comprising a force loading plate (700), wherein in the first position, the force loading plate (700) is mounted over the first end (610) or the connector (500);
the end face of the force loading disc (700) comprises a first test point (710), and a connecting line of the first test point (710) and the center of the end face of the force loading disc (700) is parallel to a preset plane;
the force application assembly (300) comprises a first pulley assembly comprising a first fixed pulley (311), a first pull rope (312) and a first balancing weight (313); one end of the first pull rope (312) is connected with the first test point (710), and the other end of the first pull rope (312) bypasses the first fixed pulley (311) and is connected with the first balancing weight (313); the first weight (313) applies the first tensile force in the first direction to the first end (610) or the second tensile force in the first direction to the connection (500) through the force loading plate (700).
7. The device for testing the stiffness of a joint of a mechanical arm according to claim 6, characterized in that an included angle θ between the first pull rope (312) and the preset plane between the first fixed pulley (311) and the first test point (710) 1 The conditions are satisfied:
0≤θ 1 ≤5°。
8. the device for testing the rigidity of a mechanical arm joint according to claim 4, wherein the force application assembly (300) further comprises two groups of second pulley assemblies, and when the mounting base (200) is in the first position, the two groups of second pulley assemblies are respectively arranged at two radial sides of the end face of the first end (610) of the mechanical arm joint (600);
the stiffness testing device of the mechanical arm joint further comprises a force loading disc (700), wherein the force loading disc (700) is sleeved and installed on the first end (610) at the first position;
the end face of the force loading disc (700) comprises two second test points (720), and the two second test points (720) are respectively arranged at two sides of the center of the end face of the force loading disc (700); and the connecting line of the center of the end face of each second test point (720) and the force loading disc (700) is perpendicular to a preset plane;
each group of the second pulley assemblies comprises a second fixed pulley (321), a second stay rope (322) and a second balancing weight (323); one end of the second pull rope (322) in the two groups of second pulley assemblies is respectively connected with one of the second test points (720), and the other end of the second pull rope bypasses the second fixed pulley (321) in the corresponding second pulley assembly and is connected with the second balancing weight (323); when the second end (620) is fixed on the mounting seat (200) in a cantilever manner, the two second balancing weights (323) apply third tensile forces to the first end (610) in opposite directions along the first direction through the force loading disc (700);
The measuring assembly (400) is configured to measure a third displacement of the first end (610) in the first direction when the two second balancing weights (323) apply the third tensile forces in the first direction to the first end (610) through the force loading discs (700), respectively.
9. The device for testing the stiffness of the mechanical arm joint according to claim 8, wherein the second guy wires (322) between the second fixed pulleys (321) and the second test points (720) in each set of the second pulley assemblies are between the second guy wires (322) and the predetermined planeIncluded angle theta 2 The conditions are satisfied:
0≤θ 2 ≤5°。
10. the device for testing the stiffness of a mechanical arm joint according to claim 8, wherein an included angle θ between the second ropes (322) in the two sets of the second pulley assemblies 3 The conditions are satisfied:
0≤θ 3 ≤5°。
11. the device for testing the stiffness of a robotic arm joint according to claim 4, wherein the force application assembly (300) further comprises a third pulley assembly comprising a third fixed pulley (331), a third pull rope (332), and a third balancing weight (333);
the stiffness testing device of the mechanical arm joint further comprises a force loading disc (700), and in the second position, the force loading disc (700) is sleeved and installed on the first end (610);
When the mounting seat (200) is positioned at the second position, one end of the third pull rope (332) is connected with the center of the end surface of the force loading disc, and the other end of the third pull rope (332) bypasses the third fixed pulley (331) and is connected with the third balancing weight (333); -the third balancing weight (333) applying a pulling force in the second direction to the first end (610) via the force loading disc (700);
the measuring assembly (400) is configured to detect displacement of the first end (610) in the second direction when the third weight (333) applies a pulling force in the second direction to the first end (610) via the force loading plate (700).
12. The device for testing the rigidity of a mechanical arm joint according to claim 11, wherein an included angle θ between the third pull rope (332) and a preset plane is located between the third fixed pulley (331) and the center of the end face of the first end (610) 4 The conditions are satisfied:
0≤θ 4 ≤5°。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320612308.6U CN219757954U (en) | 2023-03-24 | 2023-03-24 | Rigidity testing device of mechanical arm joint |
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| CN202320612308.6U CN219757954U (en) | 2023-03-24 | 2023-03-24 | Rigidity testing device of mechanical arm joint |
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