Robot tail end pose positioning system

Abstract

The utility model discloses a robot tail end pose positioning system which comprises a measured body and at least three pairs of distance measuring devices. The tested body is rigidly connected with the six-joint robot, and a plurality of tested areas distributed at different positions are arranged on the tested body; the multiple distance measuring devices are arranged on the side portion of a measured object so as to correspond to different measured areas respectively, and the multiple pairs of distance measuring devices measure the distances of the measured object in the X-axis direction, the Y-axis direction and the Z-axis direction respectively. The method has the beneficial effects that the position and posture data of the six-joint robot can be obtained at the same time based on one-time measurement of the distance measuring device and decoupling operation, and accurate positioning of the posture of the six-joint robot can be achieved through repeated measurement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of robots, in particular to a robot end position and posture positioning system. BACKGROUND

[0002] A six-joint robot is a multi-joint series, and there are many mechanical elements such as motors, reducers, bearings and connecting rods in the whole structure. The position and attitude repeatability positioning accuracy of the end thereof has a large error.

[0003] In order to quantitatively measure the repeatability positioning accuracy of the robot end, there are mainly two kinds of common methods at present. One is to use a laser calibration instrument to measure the positioning position of the robot end, but the laser calibration instrument costs more than one million yuan, so that the positioning cost of the six-joint robot is relatively high. The other is to use a pull rope sensor, but the installation of the pull rope sensor is complicated, and after the sensor is installed, the robot cannot do large range or high speed free movement, and may not be or be difficult to be applied to the repeatability positioning accuracy experiment of the six-joint robot. CONTENT OF THE INVENTION

[0004] One of the purposes of the present application is to provide a robot end position and posture positioning system which can solve at least one defect in the background art.

[0005] In order to achieve the above at least one purpose, the technical scheme adopted by the present application is: a robot end position and posture positioning system, comprising a measured body and at least three pairs of distance measuring devices; the measured body is rigidly connected with a six-joint robot, and the measured body is provided with a plurality of measured areas distributed at different positions; a plurality of distance measuring devices are arranged on the side of the measured body to correspond to different measured areas respectively, and a plurality of pairs of distance measuring devices measure the distance of the measured body in three directions of XYZ axes respectively.

[0006] Preferably, the measured body is provided with at least three measured areas, and each measured area is perpendicular to each other in the same plane.

[0007] Preferably, the measured body is a cross-shaped structure, four extended ends of the measured body correspond to form four measured areas, and the six-joint robot is connected with the center of the measured body.

[0008] Preferably, the distance measuring device has at least two pairs, wherein at least one pair of distance measuring devices is used to detect the data of the measured body in X and Y directions, and at least one pair of distance measuring devices is used to detect the data of the measured body in Z direction.

[0009] Preferably, the distance measuring devices are at least three pairs, including at least one pair of first distance measuring devices, at least one pair of second distance measuring devices and at least one pair of third distance measuring devices; the first distance measuring devices are used to collect the distance from the Z-axis direction of the measured area, two first distance measuring devices of each pair are arranged at 180° around the center of the measured body; two second distance measuring devices of each pair are arranged at 90° around the center of the measured body, one of the second distance measuring devices of each pair is used to collect the distance from the X-axis direction of the corresponding measured area, and the other second distance measuring device is used to collect the distance from the Y-axis direction of the corresponding measured area; two third distance measuring devices of each pair are respectively close to two flat measured areas, and the two third distance measuring devices are symmetrically arranged along the X direction or the Y direction to respectively collect the distance from the Y direction or the X direction of the corresponding measured area.

[0010] Preferably, the number of distance measuring devices is eight, including two pairs of first distance measuring devices, one pair of second distance measuring devices and one pair of third distance measuring devices; two pairs of first distance measuring devices correspond to four measured areas respectively.

[0011] Preferably, the distance measuring device is used to collect the distance from the end of the measured area to itself.

[0012] Preferably, the pose of the six-joint robot is represented by the relative distances O x , O y and O z from the measured area to the center O of the measured body, and the relative angles θ x , θ y and θ z ; assuming that the length of the extension end of the measured body is l, the Z-axis direction distance data collected by the two pairs of first distance measuring devices are l1 and l2 and l3 and l4 respectively, the X-axis direction and Y-axis direction distance data collected by the second distance measuring device are l5 and l6 respectively, and the distance data collected by the third distance measuring device are l7 and l8 respectively; then the pose expression of the six-joint robot is as follows:

[0013] O x =l5+l, O y =l6+l, O z =(l1+l2) / 2 or (l3+l4) / 2;

[0014] θ x =arcsin[(l1-l2) / 2l], θ y =arcsin[(l3-l4) / 2l], θ z =arcsin[(l5-l6) / 2l].

[0015] Preferably, the robot end position positioning system further comprises a base and four mounting seats, the four mounting seats are circumferentially and equally spaced arranged on the base along the center of the measured body, and the distance measuring device is correspondingly mounted on the mounting seat.

[0016] Preferably, the distance measuring device is a laser range finder.

[0017] Compared with the prior art, the application has the following beneficial effects:

[0018] Based on the one-time measurement and decoupling operation of the distance measuring device, the position and attitude data of the six-joint robot can be obtained at the same time, and through repeated measurement, the accurate positioning of the position and attitude of the six-joint robot can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 Structure diagram of the anti-falling device of the application installed on a climbing ladder.

[0020] In the figure: six-joint robot 100, measured body 200, extended end 210, first distance measuring device 310, second distance measuring device 320, third distance measuring device 330, base 410, mounting seat 420. DETAILED DESCRIPTION

[0021] In the following, the application will be further described in conjunction with specific embodiments, and it should be noted that in the description of the present application, the description of the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present application.

[0022] In the description of the present application, it should be noted that for the orientation words, such as the terms "center", "transverse", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. The orientation and positional relationship shown in the drawing is based on the orientation or positional relationship shown in the drawing, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and cannot be understood as limiting the specific protection scope of the present application.

[0023] It should be noted that the terms "first", "second" and the like in the description and in the claims of the present application are used for distinguishing between similar objects and do not necessarily have an ordinal number meaning.

[0024] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", "fixedly connected" and the like are used broadly and encompass both direct and indirect mounting, connecting, and / or fixedly connecting, and can further include mechanical mounting, connecting and / or fixedly connecting, electrical mounting, connecting and / or fixedly connecting, both or either, internal or external mounting, connecting and / or fixedly connecting. Such terms are intended to encompass the various forms of mounting, connecting, and / or fixedly connecting, and should not be construed as limited to only the forms explicitly stated herein.

[0025] In the present application, unless specifically defined otherwise, "on" or "under" of a first feature with respect to a second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, "on", "above" and "on top of" of a first feature with respect to a second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the first feature is higher than the second feature in horizontal height. "Under", "below" and "underneath" of a first feature with respect to a second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the first feature is lower than the second feature in horizontal height.

[0026] The terms "comprising" and "having" and any variations thereof in the present application and the claims are intended to cover the inclusion not of exclusive, for example, a process, method, system, product or device comprising a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] As shown in one of the preferred embodiments of the present application, Figure 1 A robot end pose positioning system includes a measured body 200 and a plurality of distance measuring devices. The measured body 200 is rigidly connected with a six-joint robot 100, so that the position and posture of the six-joint robot 100 is replaced by the position and posture of the measured body 200 to facilitate positioning. The specific structure of the six-joint robot 100 and the specific connection between the measured body 200 are known to those skilled in the art, and therefore will not be described in detail. The measured body 200 is provided with a plurality of measured areas distributed at different positions; a plurality of distance measuring devices are arranged on the side of the measured body 200 to correspond to different measured areas, and each distance measuring device detects the distance of each measured area corresponding to the measured body 200.

[0028] It can be understood that the measured body 200 is installed at the end of the six-joint robot 100 and can follow the six-joint robot 100 to run, so that when the pose of the six-joint robot 100 is positioned, the distance between each measured area of the measured body 200 can be detected by multiple distance measuring devices at the same time, and the position and attitude data of the six-joint robot 100 can be obtained at the same time based on the decoupling operation of the one-time measurement results of the distance measuring device. At the same time, the six-joint robot 100 drives the measured body 200 to rotate at multiple angles to realize multiple measurements at different positions, so as to ensure the accuracy of the pose positioning of the six-joint robot 100.

[0029] It should be understood that the method for measuring the distance between each measured area of the measured body 200 by the distance measuring device is a triangulation method, and the specific principle is known to those skilled in the art, so it will not be described in detail here. There are many specific types of distance measuring devices that can realize distance measurement, and common distance measuring devices can use laser range finders.

[0030] In this embodiment, the pose of the six-joint robot 100 includes the relative position along the XYZ three directions and the relative attitude along the XYZ three directions. The specific shape of the measured body 200 that can be used for pose positioning of the six-joint robot 100 is various, as long as the measured body 200 can have three mutually perpendicular measured areas, that is, the relative changes of the position and attitude of the six-joint robot 100 in the XYZ three directions can be measured through the corresponding measured areas of the measured body 200.

[0031] It can be understood that the measured areas on the measured body 200 can be in the same plane or not in the same plane; if the measured areas are all in the same plane, the arrangement of the distance measuring devices can be facilitated, and the data measured by the distance measuring devices does not need to be positionally corrected, so in this embodiment, the measured areas on the measured body 200 are preferably arranged in the same plane and perpendicular to each other.

[0032] Specifically, the specific structure of the measured body 200 that can form the above-mentioned measured areas is various, such as a cross structure or a cuboid structure. Since the measured body 200 with a cross structure can obtain a larger arm span under the condition of lighter mass, which is beneficial to reduce the error when calculating the attitude angle, therefore, in this embodiment, the measured body 200 is preferably a cross structure, that is, as shown in Figure 1 The four extended ends 210 of the measured body 200 can correspondingly form four measured areas, and the six-joint robot 100 is connected with the center of the measured body 200.

[0033] It should be appreciated that the four extension ends 210 of the measured body 200 can have consistent or inconsistent extension lengths; in order to simplify the subsequent pose calculation process of the six-joint robot 100, the four extension ends 210 in the embodiment preferably have equal lengths. The four extension ends 210 can be divided into two pairs according to the alignment relationship, and the two pairs of extension ends 210 are perpendicular to each other. The four extension ends 210 extend in the XY plane, and the Z direction is perpendicular to the plane in which the four extension ends 210 are located.

[0034] In the embodiment, the specific number of ranging devices capable of positioning the pose of the six-joint robot 100 is at least two pairs, and at least one pair of ranging devices is used to detect the data of the measured body 200 in the X and Y directions, and at least one pair of ranging devices is used to detect the data of the measured body 200 in the Z direction.

[0035] It can be understood that, as known from the foregoing, the pose of the six-joint robot 100 includes relative positions in the XYZ three directions and relative attitudes in the XYZ three directions. If the number of ranging devices is two pairs, only one pair of ranging devices is needed to simultaneously detect the distances in the X and Y directions of the measured regions of the measured body 200, that is, the ranging device can simultaneously measure the distances of two measured regions perpendicular to the X and Y directions. Based on the measurement results of the pair of ranging devices, the relative positions of the six-joint robot 100 in the X and Y directions and the relative attitude in the Z direction can be calculated. The other pair of ranging devices can calculate the relative attitude of the six-joint robot 100 in the X and Y directions and the relative position in the Z direction by measuring the distance of the measured body 200 in the Z direction.

[0036] It should be appreciated that if the ranging device simultaneously measures the distances of two measured regions of the measured body 200, it means that the ranging device has a positional deviation from the two measured regions to be measured, for example, the ranging device is located on the bisector of the angle formed by the two measured regions. When calculating the perpendicular distances of the ranging device from the two measured regions, a positional transformation is required, which may affect the accuracy of the calculation results. Therefore, in the embodiment, the number of ranging devices is preferably at least three pairs, which will be described in detail below for the convenience of understanding.

[0037] Specifically, as Figure 1As shown, the distance measuring devices respectively include at least one pair of first distance measuring devices 310, at least one pair of second distance measuring devices 320 and at least one pair of third distance measuring devices 330. The first distance measuring devices 310 are used to collect the distance in the Z-axis direction from the first distance measuring devices 310 to the corresponding measured region. Two first distance measuring devices 310 of each pair are arranged at 180° around the center of the measured body 200. Two second distance measuring devices 320 of each pair are arranged at 90° around the center of the measured body 200. One of the two second distance measuring devices 320 of each pair is used to collect the distance in the X-axis direction from the second distance measuring device 320 to the corresponding measured region, and the other second distance measuring device 320 is used to collect the distance in the Y-axis direction from the second distance measuring device 320 to the corresponding measured region. Two third distance measuring devices 330 of each pair are respectively close to two flat measured regions. The two third distance measuring devices 330 are symmetrically arranged along the X direction or the Y direction to respectively collect the distance in the Y direction or the X direction from the third distance measuring device 330 to the corresponding measured region.

[0038] It should be understood that, since the first distance measuring devices 310 can only measure the distance in the Z direction from the first distance measuring devices 310 to the corresponding measured region which is aligned by the first distance measuring devices 310 at a time, i.e., only the attitude deviation angle of the six-joint robot 100 in the X-axis direction or the Y-axis direction can be obtained, in order to complete the positioning of the whole attitude of the six-joint robot 100, the first distance measuring devices 310 need to be measured at least twice at different positions, which will increase the operation complexity of the measurement process. Therefore, in the embodiment, the number of distance measuring devices is further preferred to be eight, including two pairs of first distance measuring devices 310, one pair of second distance measuring devices 320 and one pair of third distance measuring devices 330; the two pairs of first distance measuring devices 310 respectively correspond to four measured regions, so that the relative position and the relative attitude of the six-joint robot 100 in the XYZ three directions can be obtained at one time.

[0039] In the embodiment, as shown in Figure 1 , the measured region is the extension end 210 of the measured body 100, so that the distance measuring devices can be measured at any position from the distance measuring devices to the corresponding measured region. However, considering that the distance from the detection point of the distance measuring device on the measured region to the center O of the measured body 200 needs to be obtained when the decoupling operation of the attitude positioning of the six-joint robot 100 is performed, in order to facilitate the calculation, the detection point of the distance measuring device can be arranged at the end position of the extension end 210 of the measured body 200, i.e., the distance measuring device is used to collect the distance from the end of the measured region to the distance measuring device.

[0040] In the embodiment, the attitude of the six-joint robot 100 is determined by the relative distances O x , O y and O z from the measured region to the center O of the measured body 200, and the relative angles θ x , θ y and θ zThe expression is performed. Then the length of the extension end 210 of the measured body 200 can be set as l, the collected Z-axis direction spacing data of the two pairs of first distance measuring devices 310 are l1 and l2 and l3 and l4, wherein l1 and l2 correspond to the spacing of the first distance measuring device 310 from the measured area parallel to the X-axis, and l3 and l4 correspond to the spacing of the first distance measuring device 310 from the measured area parallel to the Y-axis; the collected X-axis direction and Y-axis direction spacing data of the second distance measuring device 320 are l5 and l6, and the collected spacing data of the third distance measuring device 330 are l7 and l8; then the pose expression of the six-joint robot 100 is as follows:

[0041] O x = l5 + l, O y = l6 + l, O z = (l1 + l2) / 2 or (l3 + l4) / 2.

[0042] θ x = arcsin[(l1 - l2) / 2l], θ y = arcsin[(l3 - l4) / 2l], θ z = arcsin[(l5 - l6) / 2l].

[0043] It should be understood that for the calculation of the relative angle of the Z-axis direction, the spacing of the first distance measuring device 310 from the measured area parallel to the X-axis can be used, or the spacing of the first distance measuring device 310 from the measured area parallel to the Y-axis can be used. Of course, in order to further improve the calculation accuracy, the spacing of the first distance measuring device 310 from the measured area parallel to the X-axis and the spacing of the first distance measuring device 310 from the measured area parallel to the Y-axis can be used to calculate the relative angle of the Z-axis, and the average of the two relative angles is obtained.

[0044] It can also be understood that in order to improve the positioning accuracy of the pose of the six-joint robot 100, the six-joint robot 100 can drive the measured body 200 to move at different angles relative to the distance measuring device multiple times, so that the distance measuring device measures different detection points multiple times, and after obtaining sufficient information, the pose data of the six-joint robot 100 at different motion positions is calculated, and the data is averaged to improve the accuracy of the pose positioning of the six-joint robot 100.

[0045] In the embodiment, as shown in Figure 1 In order to facilitate the installation of the distance measuring device, the robot end pose positioning system further includes a base 410 and a mounting seat 420. The number of mounting seats 420 is four, and the four mounting seats 420 are arranged on the base 410 at equal intervals along the center of the measured body 200, and the distance measuring device is mounted on each mounting seat 420.

[0046] The foregoing describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-described embodiments, and the above-described embodiments and descriptions in the specification are only the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A robot end-effector pose localization system, characterized in that, include: The test object; the test object is rigidly connected to the six-joint robot, and the test object has multiple test areas distributed at different positions; as well as At least three pairs of ranging devices; multiple ranging devices are disposed on the side of the object to be measured to correspond to different areas to be measured, and multiple pairs of ranging devices measure the distance between the objects to be measured in the three directions of XYZ axis.

2. The robot end-effector pose localization system as described in claim 1, characterized in that, The test object has at least three test areas, and each test area is perpendicular to the others in the same plane.

3. The robot end-effector pose positioning system as described in claim 2, characterized in that, The object under test has a cross-shaped structure, and the four extended ends of the object under test correspond to form four test areas; the six-joint robot is connected to the center of the object under test.

4. The robot end-effector pose localization system as described in claim 3, characterized in that, The ranging device has at least three pairs, including at least one pair of first ranging devices, at least one pair of second ranging devices and at least one pair of third ranging devices; The first ranging device is used to collect the distance between itself and the measured area in the Z-axis direction. The two first ranging devices in each pair are arranged 180° around the center of the measured body. The two second ranging devices in each pair are arranged at 90° around the center of the measured object. One of the second ranging devices in each pair is used to collect the distance between itself and the corresponding measured area in the X-axis direction, and the other second ranging device is used to collect the distance between itself and the corresponding measured area in the Y-axis direction. The two third ranging devices in each pair are respectively close to the two measured areas that are aligned. The two third ranging devices are symmetrically arranged along the X or Y direction to collect the distance between themselves and the corresponding measured area in the Y or X direction.

5. The robot end-effector pose localization system as described in claim 4, characterized in that, The number of ranging devices is eight, including two pairs of first ranging devices, one pair of second ranging devices, and one pair of third ranging devices; the two pairs of first ranging devices correspond to the four measured areas respectively.

6. The robot end-effector pose localization system as described in claim 5, characterized in that, The ranging device is used to collect the distance from the end of the measured area to itself.

7. The robot end-effector pose localization system as described in claim 6, characterized in that, The pose of the six-joint robot is determined by the relative distance O from the tested area to the center O of the tested object. x O y and O z And the relative deflection angle θ from the measured area to the center O of the measured body. x θ y and θ z To represent; Let the length of the extended end of the measured object be l, the distance data collected by the two pairs of first ranging devices in the Z-axis direction be l1 and l2 and l3 and l4 respectively, the distance data collected by the second ranging device in the X-axis direction and Y-axis direction be l5 and l6 respectively, and the distance data collected by the third ranging device be l7 and l8 respectively; then the pose expression of the six-joint robot is as follows: O x = l5 + l,O y = l6 + l,O z = (l1 + l2) / 2 or (l3 + l4) / 2; θ x =arcsin[(l1-l2) / 2l],θ y =arcsin[(l3-l4) / 2l],θ z =arcsin[(l5-l6) / 2l]。 8. The robot end-effector pose localization system as described in any one of claims 4-7, characterized in that, The robot end-effector pose positioning system also includes a base and mounting bases. There are four mounting bases, which are arranged at equal intervals around the center of the object being measured on the base. The ranging device is installed on the mounting bases accordingly.

9. The robot end-effector pose localization system as described in claim 1, characterized in that, The ranging device is a laser rangefinder.

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