Mechanical arm spatial position precision repeatability testing device and method

Abstract

The invention discloses a mechanical arm spatial position precision repeatability testing device and method. The mechanical arm spatial position precision repeatability testing device comprises a probe, an L-shaped base, a fixing block, a Z-direction displacement sensor, an X-direction displacement sensor, a Y-direction displacement sensor, a data acquisition device and an upper computer. The probe is fixed on the mechanical arm; the L-shaped base is provided with an accommodating space; the fixing block is arranged on the L-shaped base and located in the containing space. The device is composed of a probe, an L-shaped base, a fixing block, a Z-direction displacement sensor, an X-direction displacement sensor, a Y-direction displacement sensor, a data acquisition device and an upper computer, the device is simple in overall structure, low in cost, high in practicability and convenient to operate, and after the testing method is adopted, the spatial position precision repeatability can be obtained at the same time, and the testing accuracy is improved. Moreover, the system can automatically give an alarm when the precision repeatability of the single-direction or spatial position exceeds a limit value, can adapt to the precision repeatability test of the multi-point spatial position of various mechanical arms or robots, and is high in adaptability.

Description

Technical Field

[0001] The present invention relates to the technical fields of robotic arms and robots, and in particular to a device and method for testing the repeatability of the spatial position accuracy of a robotic arm. Background Art

[0002] The test of the repeatability of the spatial position accuracy of a robotic arm is a process of evaluating the ability of the robotic arm to repeatedly reach the same target position within a specific working space multiple times. This test aims to verify the positioning accuracy and repeatability of the robotic arm to ensure that it can achieve the expected position accuracy when performing various tasks. The test of the repeatability of the spatial position accuracy of a robotic arm is an important link in the design and manufacturing process of the robotic arm, which helps to ensure that the robotic arm can meet the accuracy requirements in actual applications and improve production efficiency and product quality.

[0003] Currently, there are mainly two methods for testing the repeatability of the spatial position accuracy of a robotic arm: 1) Using the linear scale method, the repeatability of the position accuracy of a single direction (such as the X direction, Y direction, or Z direction) of the robotic arm can be measured; 2) Using a laser tracking system or an optical theodolite, the repeatability of the spatial position accuracy of the three directions of the robotic arm can be measured. However, the first method cannot measure the repeatability of the spatial position accuracy of the three directions simultaneously and cannot directly obtain whether the limit value is exceeded; while the second method can measure the repeatability of the spatial position accuracy, but the system is complex, the cost is high, and it cannot directly obtain whether the limit value is exceeded. Therefore, it is necessary to study a solution to solve the above problems. Summary of the Invention

[0004] In view of this, in view of the deficiencies of the existing technology, the main purpose of the present invention is to provide a device and method for testing the repeatability of the spatial position accuracy of a robotic arm, which can effectively solve the problems of the existing method for testing the repeatability of the spatial position accuracy of a robotic arm, such as complex system, high cost, and inability to directly obtain whether the limit value is exceeded.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: A device for testing the repeatability of the spatial position accuracy of a robotic arm includes a probe, an L-shaped base, a fixing block, a Z-direction displacement sensor, an X-direction displacement sensor, a Y-direction displacement sensor, a data acquisition device, and a host computer; the probe is fixed on the robotic arm; the L-shaped base has an accommodation space; the fixing block is arranged on the L-shaped base and is located in the accommodation space; the Z-direction displacement sensor is fixed on the fixing block and extends vertically; the X-direction displacement sensor and the Y-direction displacement sensor are both arranged on the L-shaped base and are located beside the Z-direction displacement sensor, the X-direction displacement sensor extends horizontally, and the Y-direction displacement sensor extends longitudinally; the data acquisition device collects the test data of the Z-direction displacement sensor, the X-direction displacement sensor, and the Y-direction displacement sensor through a cable; the host computer transmits the test data of the data acquisition device through a data line.

[0006] Preferably, the probe has a bolt portion which is fixedly connected to the robotic arm.

[0007] Preferably, the four sides of the contact surface between the probe and the Z-direction displacement sensor are all chamfered, and the radius R of the chamfer is 2 mm to 5 mm.

[0008] Preferably, the four sides of the contact surface between the probe and the X-direction displacement sensor are all chamfered, and the radius R of the chamfer is 2 mm to 5 mm.

[0009] Preferably, the four sides of the contact surface between the probe and the Y-direction displacement sensor are all chamfered, and the radius R of the chamfer is 2 mm to 5 mm.

[0010] Preferably, the fixing block is horizontally arranged, and the fixing block is arranged on the L-shaped base in a vertically adjustable position.

[0011] Preferably, two waist-shaped holes are formed in the L-shaped base, and two fixing bolts respectively pass through the two waist-shaped holes and are fixedly connected to the fixing block.

[0012] Preferably, the length of the two waist-shaped holes in the vertical direction is 12 mm to 20 mm.

[0013] A method for testing the repeatability of the spatial position accuracy of a robotic arm, using a device for testing the repeatability of the spatial position accuracy of a robotic arm, includes the following steps: (1) Start the data acquisition device, and the Z-direction displacement sensor, the X-direction displacement sensor, and the Y-direction displacement sensor respectively sense the Z-direction, X-direction, and Y-direction displacement data of the probe; (2) The data acquisition module of the upper computer collects the X / Y / Z-direction displacement data collected by the data acquisition device; (3) The data storage module of the upper computer stores the collected X / Y / Z-direction displacement data; (4) The data processing module of the upper computer processes the stored X / Y / Z-direction displacement data, obtains the position accuracy repeatability results in the X / Y / Z directions, and then obtains the spatial position accuracy repeatability results after adding the corresponding correction coefficients to each direction; (5) Based on the position accuracy repeatability results obtained by the data processing module of the upper computer, if the repeatability of a single direction or the spatial position accuracy exceeds the limit value S, start the alarm program and let the robotic arm or robot stop according to the emergency program; The main calculation formula of the data processing module of the upper computer is as follows: X-direction position accuracy repeatability s x： , Y-direction position accuracy repeatability s y : , Z-axis position accuracy repeatability z： , Spatial position accuracy repeatability S: S=as x +bs y +cs z , where a, b and c are correction coefficients; Limit value K: X-axis limit value K x ,S x ≤K x ; Y-axis limit value K y ,S y ≤K y ; Z-axis limit value K,S z ≤K z ; Space limit value K, S≤K.

[0014] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical solution that: The device is composed of a probe, an L-shaped base, a fixed block, a Z-direction displacement sensor, an X-direction displacement sensor, a Y-direction displacement sensor, a data acquisition device and a host machine. The overall structure is simple, the cost is low, the practicability is strong, and the operation is convenient. After the test method of the present invention is used, not only can the spatial position accuracy repeatability be obtained at the same time, but also an automatic alarm can be given when the single-direction or spatial position accuracy repeatability exceeds the limit value. At the same time, it can adapt to the multi-point spatial position accuracy repeatability test of multiple mechanical arms or robots, and has strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a preferred embodiment of the present invention; Figure 2 yes Figure 1 Schematic diagram from another angle; Figure 3 is an enlarged schematic diagram of a probe in a preferred embodiment of the present invention; Figure 4 is an enlarged schematic diagram of an L-shaped base in a preferred embodiment of the present invention; Figure 5 It is a schematic diagram of the execution flow of the host computer in the preferred embodiment of the present invention.

[0016] Description of the accompanying drawings: 10. Probe 11. Bolt 20. L-shaped base 21. Accommodation space 22. Waist-shaped hole 23. Mounting hole 30. Fixed block 41. Z-direction displacement sensor 42. X-direction displacement sensor 43. Y-direction displacement sensor 50. Data acquisition device 60. Host computer 70. Robot arm Detailed implementation manner

[0017] Please refer to Figures 1 to 4 as shown, which shows the specific structure of a robot arm spatial position accuracy repeatability test device according to a preferred embodiment of the present invention, including a probe 10, an L-shaped base 20, a fixed block 30, a Z-direction displacement sensor 41, an X-direction displacement sensor 42, a Y-direction displacement sensor 43, a data acquisition device 50, and a host computer 60.

[0018] The probe 10 is fixed on the robot arm 70; in this embodiment, the probe 10 has a bolt portion 11, and the bolt portion 11 is fixedly connected to the robot arm 70, which is convenient for disassembly and assembly. Also, the four sides of the contact surface between the probe 10 and the Z-direction displacement sensor 41 are all chamfered, and the radius R of the chamfer is 2 mm to 5 mm. The four sides of the contact surface between the probe 10 and the X-direction displacement sensor 42 are all chamfered, and the radius R of the chamfer is 2 mm to 5 mm. The four sides of the contact surface between the probe 10 and the Y-direction displacement sensor 43 are all chamfered, and the radius R of the chamfer is 2 mm to 5 mm. This can greatly reduce the damage rate of each displacement sensor during the test.

[0019] The L-shaped base 20 has a receiving space 21. In this embodiment, two waist-shaped holes 22 are opened on the L-shaped base 20, and both waist-shaped holes 22 extend vertically, and the lengths of the two waist-shaped holes 22 in the vertical direction are both 12 mm to 20 mm, so as to adapt to the spatial position accuracy repeatability test of different positions of the robot arm 70 or the robot. Also, two mounting holes 23 are opened on the L-shaped base 20, and the two mounting holes 23 are respectively located beside the two waist-shaped holes 22.

[0020] The fixed block 30 is arranged on the L-shaped base 20 and is located in the receiving space 21. In this embodiment, the fixed block 30 is horizontally arranged, and the fixed block 30 is arranged on the L-shaped base 20 so that its position can be adjusted vertically up and down. Specifically, two fixing bolts (not shown in the figure) respectively pass through the two waist-shaped holes 22 and are fixedly connected to the fixed block 30, and the fixed block 30 is of a square block structure.

[0021] The Z-direction displacement sensor 41 is fixed on the fixed block 30 and extends vertically; the X-direction displacement sensor 42 and the Y-direction displacement sensor 43 are both arranged on the L-shaped base 20 and beside the Z-direction displacement sensor 41. The X-direction displacement sensor 42 extends horizontally, and the Y-direction displacement sensor 43 extends longitudinally. In the embodiment, the Z-direction displacement sensor 41 is fixed at the center position of the fixed block 30 by bolts, and the X-direction displacement sensor 42 and the Y-direction displacement sensor 43 are respectively fixed in the two mounting holes 23 by bolts.

[0022] The data acquisition device 50 collects the test data of the Z-direction displacement sensor 41, the X-direction displacement sensor 42, and the Y-direction displacement sensor 43 through cables.

[0023] The host computer 60 transmits the test data of the data acquisition device 50 through a data cable.

[0024] As Figure 5 shown, the present invention also discloses a method for testing the repeatability of the spatial position accuracy of a robotic arm. Using the aforementioned device for testing the repeatability of the spatial position accuracy of a robotic arm, it includes the following steps: (1) Start the data acquisition device 50, and the Z-direction displacement sensor 41, the X-direction displacement sensor 42, and the Y-direction displacement sensor 43 respectively sense the Z-direction, X-direction, and Y-direction displacement data of the probe 10.

[0025] (2) The data acquisition module of the host computer 60 collects the X / Y / Z-direction displacement data collected by the data acquisition device 50.

[0026] (3) The data storage module of the host computer 60 stores the collected X / Y / Z-direction displacement data.

[0027] (4) The data processing module of the host computer 60 processes the stored X / Y / Z-direction displacement data, obtains the repeatability results of the X / Y / Z-direction position accuracy, and then obtains the repeatability results of the spatial position accuracy after adding the corresponding correction coefficients to each direction.

[0028] (5) Based on the repeatability results of the position accuracy obtained by the data processing module of the host computer 60, if the repeatability of a single direction or the spatial position accuracy exceeds the limit value S, start the alarm program to make the robotic arm 70 or the robot stop according to the emergency program.

[0029] The main calculation formulas of the data processing module of the host computer 60 are as follows: X-direction position accuracy repeatability s x： , Y-direction position accuracy repeatability s y : , Z-axis position accuracy repeatability z： , Spatial position accuracy repeatability S: S=as x +bs y +cs z , where a, b and c are correction coefficients; The preferred value range of a is (0,2]; The preferred value range of b is (0,3]; The preferred value range of c is (0,0.8].

[0030] Limit value K: X-axis limit value K x , the preferred value range is (0,0.4], S x ≤K x ; Y-axis limit value K y , the preferred value range is (0,0.4], S y ≤K y ;; Z-axis limit value K z , the preferred value range is (0,0.6] ,S z ≤K z ; The spatial limit value K preferably has a value range of [0.01,1], S≤K.

[0031] The design focus of the present invention is: the device is composed of a probe, an L-shaped base, a fixed block, a Z-direction displacement sensor, an X-direction displacement sensor, a Y-direction displacement sensor, a data acquisition device and a host machine. The overall structure is simple, the cost is low, the practicability is strong, and the operation is convenient. After the test method of the present invention is used, not only can the spatial position accuracy repeatability be obtained at the same time, but also the single-direction or spatial position accuracy repeatability can automatically alarm when it exceeds the limit value. At the same time, it can adapt to the multi-point spatial position accuracy repeatability test of multiple mechanical arms or robots, and has strong adaptability.

[0032] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A robot arm spatial position accuracy repeatability testing device, characterized by: The invention comprises a probe, an L-shaped base, a fixing block, a Z-direction displacement sensor, an X-direction displacement sensor, a Y-direction displacement sensor, a data acquisition device and a host computer; the probe is fixed on the mechanical arm; the L-shaped base has an accommodating space; the fixing block is arranged on the L-shaped base and is located in the accommodating space; the Z-direction displacement sensor is fixed on the fixing block and extends vertically; the X-direction displacement sensor and the Y-direction displacement sensor are both arranged on the L-shaped base and are located beside the Z-direction displacement sensor, the X-direction displacement sensor extends horizontally, and the Y-direction displacement sensor extends longitudinally; the data acquisition device collects test data of the Z-direction displacement sensor, the X-direction displacement sensor and the Y-direction displacement sensor through cables; the host computer transmits the test data of the data acquisition device through a data line; the probe has a bolt part, and the bolt part is fixedly connected to the mechanical arm; the fixing block is arranged horizontally, and the fixing block can be arranged on the L-shaped base in a manner that the position can be adjusted vertically upward and downward.

2. A mechanical arm spatial position accuracy repeatability testing device as claimed in claim 1, characterized in that: The four sides of the contact surface between the probe and the Z-direction displacement sensor are all rounded, and the radius R of the rounded corner is 2mm to 5mm.

3. A mechanical arm spatial position accuracy repeatability testing device as claimed in claim 1, characterized in that: The four sides of the contact surface between the probe and the X-axis displacement sensor are all rounded, and the radius R of the rounded corner is 2mm to 5mm.

4. A mechanical arm spatial position accuracy repeatability testing device as claimed in claim 1, characterized in that: The four sides of the contact surface between the probe and the Y-axis displacement sensor are all rounded, and the radius R of the rounded corner is 2mm to 5mm.

5. A mechanical arm spatial position accuracy repeatability testing device as claimed in claim 1, characterized in that: The L-shaped base is provided with two waist-shaped holes, and two fixing bolts respectively pass through the two waist-shaped holes and are fixedly connected with the fixing block.

6. A mechanical arm spatial position accuracy repeatability testing device as claimed in claim 5, characterized in that: The length of the two waist-shaped holes in the vertical direction is 12 mm to 20 mm.

7. A method for testing the repeatability of spatial position accuracy of a robotic arm, characterized by: A mechanical arm spatial position accuracy repeatability testing device as claimed in any one of claims 1 to 6 is used, comprising the following steps: (1) Start the data acquisition device, and use the Z-axis displacement sensor, X-axis displacement sensor, and Y-axis displacement sensor to sense the displacement data of the probe in the Z-axis, X-axis, and Y-axis directions respectively; (2) The data acquisition module of the host computer collects the X / Y / Z displacement data collected by the data acquisition device; (3) The data storage module of the host computer stores the collected X / Y / Z displacement data; (4) The data processing module of the host computer processes the stored X / Y / Z displacement data to obtain the position accuracy repeatability results in the X / Y / Z directions, and then obtains the spatial position accuracy repeatability results by adding the corresponding correction coefficient to each direction; (5) Based on the position accuracy repeatability results obtained by the data processing module of the host computer, if the single-direction or spatial position accuracy repeatability exceeds the limit value S, the alarm program is activated to stop the manipulator or robot according to the emergency procedure; The main calculation formula of the data processing module of the host computer is as follows: X-axis position accuracy repeatability x： ， Y-axis position accuracy repeatability y : ， Z-axis position accuracy repeatability z： ， Spatial position accuracy repeatability S: S=as x +bs y +cs z , where a, b and c are correction coefficients; Limit value K: X-axis limit value K x ,S x ≤K x ; Y-axis limit value K y ,S y ≤K y ; Z-axis limit value K,S z ≤K z ; Space limit value K, S≤K.

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