Industrial robot tail end drill bit parameter acquisition device and method

Abstract

The invention discloses an industrial robot tail end drill bit parameter obtaining device which comprises a sleeve, a reciprocating push rod mechanism and a target ball fixing mechanism. According to the industrial robot tail end drill bit parameter obtaining device, switching of two use modes is achieved through the expansion sleeve adding / removing mechanism, under the use mode of the expansion sleeve adding mechanism, one end of the reciprocating push rod mechanism stretches into one end of the sleeve, and the target ball fixing mechanism is installed at the end, stretching out of the sleeve, of the reciprocating push rod mechanism; the expansion sleeve mechanism is mounted at the other end of the sleeve and matched with the sleeve for mounting a drill bit; in the using mode of removing the expansion sleeve mechanism, one end of the reciprocating push rod mechanism extends into one end of the sleeve, the target ball fixing mechanism is installed at the end, extending out of the sleeve, of the reciprocating push rod mechanism, and a drill bit extends into the other end of the sleeve. On one hand, the method can be used for obtaining drill bit pose parameters; on the other hand, the method can be used for drill length parameter acquisition.

Description

Technical Field

[0001] The invention relates to a device and method for obtaining parameters of a drill bit at the end of an industrial robot, and belongs to the technical field of industrial robot automation. Background Art

[0002] The robot end effector is a crucial component of robotics technology, which directly affects the robot's operating accuracy, efficiency and reliability. Among the many end effectors, the end drill is widely used in automobile manufacturing, aerospace, precision machining and other fields, and its calibration accuracy is of great significance to ensure product quality. With the continuous improvement of industrial automation level, the calibration technology of the robot end drill faces many challenges.

[0003] At present, the difficulties in calibrating robot end drills at home and abroad include extremely high requirements for accuracy and repeatability. This is mainly manifested in the fact that when the robot end drill performs tasks such as drilling and tapping, the position accuracy and repeatability requirements are extremely high.

[0004] The coordination control of multiple degrees of freedom is difficult, mainly because the drill bit at the end of the robot usually has multiple degrees of freedom. How to achieve precise coordination control of these degrees of freedom during the calibration process is a key issue in calibration technology.

[0005] The complexity and real-time nature of the calibration algorithm are mainly reflected in the fact that the calibration algorithm of the robot end drill needs to consider factors such as nonlinearity and time-varying properties, which makes the algorithm design complicated. The limitations of sensor technology are mainly reflected in the fact that sensors are important tools for robot end drill calibration, but current sensor technology has limitations in terms of accuracy, stability, and anti-interference capabilities. Poor environmental adaptability is mainly reflected in the fact that when the robot end drill is operating in an industrial field, it may face complex environmental factors such as temperature changes, vibrations, and electromagnetic interference. Summary of the invention

[0006] The present invention provides an industrial robot end drill bit parameter acquisition device and method, which realizes switching between two usage modes by attaching / removing an expansion sleeve mechanism. In the two usage modes, on the one hand, it can be used to realize the acquisition of drill bit posture parameters; on the other hand, it can be used to acquire drill bit length parameters.

[0007] The technical solution of the present invention is:

[0008] According to a first aspect of the present invention, there is provided an industrial robot end drill bit parameter acquisition device, comprising a sleeve 30, a reciprocating push rod mechanism, and a target ball fixing mechanism; the industrial robot end drill bit parameter acquisition device realizes switching between two usage modes by attaching / removing an expansion sleeve mechanism, in the usage mode of attaching the expansion sleeve mechanism, one end of the reciprocating push rod mechanism extends into one end of the sleeve 30, the end of the reciprocating push rod mechanism extending out of the sleeve 30 is installed with the target ball fixing mechanism, the expansion sleeve mechanism is installed at the other end of the sleeve 30 and the two cooperate to install the drill bit; in the usage mode of removing the expansion sleeve mechanism, one end of the reciprocating push rod mechanism extends into one end of the sleeve 30, the end of the reciprocating push rod mechanism extending out of the sleeve 30 is installed with the target ball fixing mechanism, and the other end of the sleeve 30 is used for the drill bit to be inserted.

[0009] Furthermore, the expansion sleeve mechanism comprises an expansion sleeve outer sleeve 4 , an expansion sleeve inner sleeve 5 , a first screw 3 , and a second screw 6 ; the expansion sleeve inner sleeve 5 extends into the expansion sleeve outer sleeve 4 and is fastened by the first screw 3 and the second screw 6 .

[0010] Furthermore, the reciprocating push rod mechanism includes a connecting rod 10, a push plate 11, and a movable snap-in device 17, and the industrial robot end drill bit parameter acquisition device also includes a grating ruler 25 installed on the inner side of a sleeve 30; one end of the push plate 11 is connected to one end of the connecting rod 10, and a target ball fixing mechanism is installed on the other end of the connecting rod 10; an arc-shaped contact groove 20 is provided at the other end of the push plate 11, and a movable snap-in device 17 is installed on the connecting rod 10; the connecting rod 10 is movably arranged in a first preset direction in the sleeve 30, and the arc-shaped contact groove 20 is brought into contact with the end of the drill bit by moving the connecting rod 10 along the first preset direction to read the information of the grating ruler 25.

[0011] Furthermore, the movable buckle device 17 includes a spring mounting portion 21, a telescopic rod 22, and a spring 23; a plurality of fixed buckle holes are arranged at intervals along a first preset direction on the sleeve 30; the spring mounting portion 21 is arranged on the connecting rod 10, and grooves extending along a second preset direction are arranged on two opposite sides of the spring mounting portion 21 close to the inner side of the sleeve 30, one end of the spring 23 is connected to the groove, and the other end of the spring 23 is connected to one end of the telescopic rod 22, and the other end of the telescopic rod 22 is a free end; the telescopic rod 22 is movably arranged along the second preset direction by the telescopic movement of the spring 23; the telescopic rod 22 is matched with the fixed buckle hole at the required position by the movement of the connecting rod 10 along the first preset direction.

[0012] Furthermore, the industrial robot end drill bit parameter acquisition device also includes:

[0013] A first guide structure 18, which is disposed inside the sleeve 30 and extends along a first preset direction, and is used to guide the movement of the telescopic rod 22 in the mobile buckle device 17 along the first preset direction;

[0014] The second guide structure 19 is disposed inside the sleeve 30 and extends along a first preset direction. The second guide structure 19 is used to guide the movement of the push plate 11 in the reciprocating push rod mechanism along the first preset direction.

[0015] Furthermore, the target ball fixing mechanism includes a mounting frame 14, a first target seat fixing position 1, a second target seat fixing position 7, a third target seat fixing position 8, and a fourth target seat fixing position 9; the first target seat fixing position 1, the second target seat fixing position 7, the third target seat fixing position 8, and the fourth target seat fixing position 9 are installed on the mounting frame 14 in an interval arrangement; the second target seat fixing position 7 and the fourth target seat fixing position 9 are symmetrically arranged based on the axial direction of the sleeve 30.

[0016] According to a second aspect of the present invention, a method for obtaining parameters of a drill bit at the end of an industrial robot is provided, which is performed using any of the above-mentioned devices for obtaining parameters of a drill bit at the end of an industrial robot, and is used to obtain the position and posture of the drill bit. The obtaining steps are as follows:

[0017] Step 1: fix the industrial robot end drill bit parameter acquisition device with an additional expansion sleeve mechanism on the industrial robot end drill bit 26, and install three target balls 24 on the target seat fixing position; put the laser tracker 28 on one side of the industrial robot, turn on the industrial robot, and put it in a normal working state; face the laser tracker 28 to the target seat fixing position in the target ball fixing mechanism, and make sure there is no obstacle between the laser tracker 28 and the target seat fixing position, and turn on the laser tracker 28 for preheating;

[0018] Step 2, when the robot is in the zero position state, use the laser tracker 28 and SA software to collect a point for each of the three target balls 24 installed on the target seat fixing position, that is, obtain the target ball center coordinate positions P1, P2, and P3 respectively, and use these three points on the SA software to fit a plane as the first plane; it is known that in the design, the distance from the first side surface of the fixed position of the target ball fixing mechanism to the sleeve axis is D, the radius of the target ball is R, and the distance from the center point P of the mounting frame 14 to the arc-shaped contact groove 20 on the push plate 11 plane is H; then translate the first plane by a distance L, and use the translated plane as the second plane, so that the second plane coincides with the sleeve axis; wherein L=RD;

[0019] Step three, based on the second plane, establish a measurement coordinate system; the establishment of the measurement coordinate system is specifically as follows: the center point P of the mounting frame 14 is taken as the origin of the measurement coordinate system, the sleeve axis is the Z-axis direction of the measurement coordinate system, the positive direction of the Z-axis points to the expansion sleeve mechanism, the X-axis direction is the direction perpendicular to the second plane, the positive direction of the X-axis points to the first plane, and the Y-axis direction is determined according to the right-hand rule, that is, the measurement coordinate system O is completed. j -X j Y j Z j Establish; according to the position of the end of the drill bit 26 in the measurement coordinate system, obtain the transformation relationship in the drill bit coordinate system is the translation vector and the rotation matrix constitute;

[0020] Step 4: Calibrate the industrial robot end flange coordinate system O f -X f Y f Z f The transformation relationship is the translation vector and the rotation matrix constitute;

[0021] Step 5: According to and Obtain the position of the drill bit end

[0022] Furthermore, the fixing position of the target ball fixing mechanism is a cylindrical structure with an open upper end and a hollow interior, and an inner end surface of a closed end surface in the fixing position of the target ball fixing mechanism which is parallel to the sleeve axis is used as a first side surface of the fixing position of the target ball fixing mechanism.

[0023] Furthermore, the transformation relationship in the drill bit coordinate system is The expression is:

[0024]

[0025] In the formula, the translation vector P0=[Px Py Pz] T -[L 0 0] T +[0 0 H] T , P0 represents the position of the end of the drill bit 26 in the measurement coordinate system, [Px Py Pz] represents the coordinates of P2 in the first plane; P = [Px Py Pz] T -[L 0 0] T Indicates the position of the center point P of the mounting frame 14 in the measurement coordinate system.

[0026] Furthermore, the step four is specifically as follows: first, drive the industrial robot 29 to the zero position state, rotate the fifth joint of the industrial robot 29, and collect the position coordinates of the points at intervals of 2°, then fit the above-mentioned measurement points into a circle in the SA software, and use the normal vector of the circle as the five-axis axis, that is, the Z-axis direction of the base coordinate system of the industrial robot 29; similarly, adjust the industrial robot 29 to the zero position state again, rotate the sixth joint of the industrial robot 29 alone, and collect the position coordinates of the points at intervals of 2° to obtain the six-axis axis of the industrial robot 29; then, use the SA software to find the common perpendicular line between the five-axis axis and the six-axis axis, that is, the X-axis of the coordinate system of the industrial robot terminal flange 27; then, cross multiply in the SA software to obtain the Y-axis direction of the coordinate system of the industrial robot terminal flange 27; finally, offset the length of the six-axis of the robot downward in the opposite direction of the Z-axis of the coordinate system of the robot terminal flange 27 as the origin of the coordinate system of the industrial robot terminal flange 27, thereby obtaining the coordinate system O of the industrial robot terminal flange 27 f -X f Y f Z f , and then we can get the transformation relationship

[0027] The beneficial effects of the present invention are:

[0028] First, it can ensure the coincidence of the drill bit axis and the sleeve axis to the greatest extent, and can improve the accuracy of obtaining the drill bit's position and posture; it is mainly manifested in that: through the reciprocating push rod mechanism, during the up and down movement, it moves on the second guide structure to ensure the uniqueness of the trajectory; it is fixed by a moving clip device, and the moving clip device moves in the first guide structure to ensure the uniqueness of the trajectory; the second guide structure and the first guide structure are distributed on the inner side of the sleeve in parallel to each other, ensuring the fixity and uniqueness of the trajectory; more importantly, installing an expansion sleeve at the top of the sleeve can clamp the drill bit well and ensure that the drill bit and the inner sleeve of the expansion sleeve are coaxial, thereby further ensuring the coincidence of the drill bit axis and the sleeve axis.

[0029] Second, in order to accurately fix the reciprocating push rod mechanism, the present invention adopts a mobile clip device, which moves the reciprocating push rod so that the sleeve and the drill bit are in a suitable position. At this time, the telescopic rod in the mobile clip device is in an extended state under the action of the spring force, that is, at the fixed clip hole, thereby achieving fixation of the position of the drill bit.

[0030] Third, the present invention adopts a sleeve and a mobile buckle device, which makes the fixation and posture acquisition process of the drill bit simpler and reduces the difficulty of operation. The grating ruler is used to directly read the drill bit length data without complicated calculations, thereby improving the measurement efficiency.

[0031] Fourthly, the method of the present invention can directly obtain the position and posture of the end of the drill bit, replacing the traditional multi-point tip calibration method, and providing accurate position and posture information for industrial robot processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 It is a cross-sectional view of the expansion sleeve mechanism of the present invention;

[0034] Figure 3 A three-dimensional diagram of the expansion sleeve mechanism of the present invention;

[0035] Figure 4 It is a cross-sectional view of the sleeve structure of the present invention;

[0036] Figure 5 A three-dimensional diagram of the sleeve structure of the present invention;

[0037] Figure 6 It is a schematic diagram of the reciprocating push rod mechanism of the present invention;

[0038] Figure 7 It is a cross-sectional view of the matching structure of the sleeve and reciprocating push rod mechanism of the present invention;

[0039] Figure 8 This is a cross-sectional view of the structure of the mobile buckle device of the present invention;

[0040] Fig. 9 It is a flow chart of the drill bit end posture method of the present invention;

[0041] Fig.10 Schematic diagram of the coordinate system in the drill bit end posture method of the present invention;

[0042] Fig.11 It is a schematic diagram of the position calibration system of the drill bit at the end of the industrial robot of the present invention;

[0043] The numbers in the figure are: 1-first fixed target seat position, 2-fastening screw, 3-first screw, 4-expansion sleeve outer sleeve, 5-expansion sleeve inner sleeve, 6-second screw, 7-second fixed target seat position, 8-third fixed target seat position, 9-fourth fixed target seat position, 10-connecting rod, 11-push plate, 12-first fixed clamping hole, 13-second fixed clamping hole, 14-mounting frame, 15-third fixed clamping hole, 16-fourth fixed clamping hole, 17-movable buckle device, 18-first guide structure, 19-second guide structure, 20-arc contact groove, 21-spring mounting part, 22-telescopic rod, 23-spring, 24-target ball, 25-grating ruler, 26-drill bit, 27-robot end flange, 28-laser tracker, 29-industrial robot, 30-sleeve, 31-target ball center. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other arbitrarily without conflict.

[0045] The industrial robot end drill bit parameter acquisition device provided by the present invention can adopt any one of an additional expansion sleeve mechanism and a removal expansion sleeve mechanism. The following is a description of an embodiment of the additional expansion sleeve mechanism:

[0046] Example 1: Figure 1-11 As shown, according to the first aspect of an embodiment of the present invention, there is provided an industrial robot end drill bit parameter acquisition device, comprising a sleeve 30, a reciprocating push rod mechanism, and a target ball fixing mechanism; the industrial robot end drill bit parameter acquisition device is additionally provided with an expansion sleeve mechanism, and when the additional expansion sleeve mechanism is used, one end of the reciprocating push rod mechanism extends into one end of the sleeve 30, and the target ball fixing mechanism is installed at one end of the reciprocating push rod mechanism extending out of the sleeve 30, and the expansion sleeve mechanism is installed at the other end of the sleeve 30 and the two cooperate to install the drill bit.

[0047] Furthermore, the expansion sleeve mechanism comprises an expansion sleeve outer sleeve 4 , an expansion sleeve inner sleeve 5 , a first screw 3 , and a second screw 6 ; the expansion sleeve inner sleeve 5 extends into the expansion sleeve outer sleeve 4 and is fastened by the first screw 3 and the second screw 6 .

[0048] Furthermore, the reciprocating push rod mechanism includes a connecting rod 10, a push plate 11, and a movable snap-in device 17, and the industrial robot end drill bit parameter acquisition device also includes a grating ruler 25 installed on the inner side of a sleeve 30; one end of the push plate 11 is connected to one end of the connecting rod 10, and a target ball fixing mechanism is installed on the other end of the connecting rod 10; an arc-shaped contact groove 20 is provided at the other end of the push plate 11, and a movable snap-in device 17 is installed on the connecting rod 10; the connecting rod 10 is movably arranged in a first preset direction in the sleeve 30, and the arc-shaped contact groove 20 is brought into contact with the end of the drill bit by moving the connecting rod 10 along the first preset direction to read the information of the grating ruler 25.

[0049] Specifically, the additional expansion sleeve mechanism is used as follows:

[0050] In this mode, an expansion sleeve mechanism is added, and the expansion sleeve outer sleeve 4 and the sleeve 30 are interference fit. After the expansion sleeve mechanism is installed on the sleeve, it is tightened again by the left and right set screws 2. When the screws are tightened, the inner sleeve and the outer sleeve are elastically deformed and closely adhere to the surface of the drill bit and the sleeve, generating a huge friction force, causing the inner sleeve to expand outward and the outer sleeve to expand inward, thereby achieving the clamping and fixation of the drill bit.

[0051] Furthermore, the movable buckle device 17 includes a spring mounting portion 21, a telescopic rod 22, and a spring 23; the sleeve 30 is provided with a plurality of fixed buckle holes arranged at intervals along a first preset direction; illustratively, Figure 7 As shown, four fixing holes are shown, namely, the second fixing hole 13, the third fixing hole 15, the first fixing hole 12, and the fourth fixing hole 16 arranged in sequence from top to bottom; the spring mounting portion 21 is arranged on the connecting rod 10, and the two sides of the spring mounting portion 21 that are arranged opposite to each other and close to the inner side of the sleeve 30 are provided with grooves extending along the second preset direction, one end of the spring 23 is connected to the groove, and the other end of the spring 23 is connected to one end of the telescopic rod 22, and the other end of the telescopic rod 22 is a free end; the telescopic rod 22 is movably arranged along the second preset direction by the telescopic movement of the spring 23; the telescopic rod 22 is matched with the fixing hole at the desired position by the movement of the connecting rod 10 along the first preset direction; the first preset direction is perpendicular to the second preset direction.

[0052] Furthermore, the industrial robot end drill bit parameter acquisition device also includes:

[0053] A first guide structure 18, which is disposed inside the sleeve 30 and extends along a first preset direction, and is used to guide the movement of the telescopic rod 22 in the mobile buckle device 17 along the first preset direction;

[0054] The second guide structure 19 is arranged inside the sleeve 30 and extends along the first preset direction. The second guide structure 19 is used to guide the movement of the push plate 11 in the reciprocating push rod mechanism along the first preset direction. In specific applications, a protrusion is provided on the push plate 11, and the protrusion is slidably matched with the second guide structure 19 to guide the movement of the reciprocating push rod mechanism along the first preset direction.

[0055] Furthermore, the target ball fixing mechanism includes a mounting frame 14, a first target seat fixing position 1, a second target seat fixing position 7, a third target seat fixing position 8, and a fourth target seat fixing position 9; the first target seat fixing position 1, the second target seat fixing position 7, the third target seat fixing position 8, and the fourth target seat fixing position 9 are installed on the mounting frame 14 in an interval arrangement; the second target seat fixing position 7 and the fourth target seat fixing position 9 are symmetrically arranged based on the axial direction of the sleeve 30.

[0056] Exemplarily, the mounting frame 14 is cross-shaped and used to install four target seat fixing positions, wherein two target seat fixing positions are symmetrical based on the axis direction of the sleeve, thereby realizing position acquisition. The fixing position of the target ball fixing mechanism is a hollow cylindrical structure with an open upper end.

[0057] In specific applications, it can be used in conjunction with an industrial robot 29 and a laser tracker 28; the industrial robot 29 is a six-degree-of-freedom robot, the drill bit 26 is mounted on the end flange 27 of the industrial robot, and the end drill bit position acquisition device of the present invention is mounted on the drill bit 26, and used in the use mode described in this embodiment. In this use mode, after the sleeve 30 is fixed, the two target balls 24 are mounted on the second target seat fixing position 7 and the fourth target seat fixing position 9, and one target ball 24 is installed in one of the first target seat fixing position 1 or the third target seat fixing position 8. The reasonable centering of the sleeve 30 can be well achieved through the above-described target ball 24 installation method. The laser tracker 28 and the target ball 24 can be used to measure the six-degree-of-freedom end position of the industrial robot 29. Specifically, the laser emitted by the laser tracker 28 is on the corner cube prism of the target ball 24, and after reflection from the prism, the three-dimensional position of the target ball 24 can be measured, and the position information can be obtained by processing through the SA software.

[0058] According to a second aspect of an embodiment of the present invention, a method for obtaining parameters of a drill bit at the end of an industrial robot is provided, which is performed using the above-mentioned device for obtaining parameters of a drill bit at the end of an industrial robot, and is used to obtain the position and posture of the drill bit. The obtaining steps are as follows:

[0059] Step 1: fix the industrial robot end drill bit parameter acquisition device with an additional expansion sleeve mechanism on the industrial robot end drill bit 26, and install three target balls 24 on the target seat fixing position; put the laser tracker 28 on one side of the industrial robot, turn on the industrial robot, and put it in a normal working state; face the laser tracker 28 to the target seat fixing position in the target ball fixing mechanism, and make sure there is no obstacle between the laser tracker 28 and the target seat fixing position, and turn on the laser tracker 28 for preheating;

[0060] Step 2: When the robot is in the zero position, use the laser tracker 28 and SA software to collect a point for each of the three target balls 24 installed on the target base, that is, obtain the coordinate positions of the center of the target balls as P1, P2, and P3, respectively. Figure 7 As shown, these three points are used to fit a plane on the SA software as the first plane, which is Fig.10 As shown in the planes P1 and P2 (which can also be understood as P1 and P3), it is known that when designing the present invention, the distance from the first side surface of the fixed position of the target ball fixing mechanism to the sleeve axis is D, the radius of the target ball is R, and the distance from the center point P of the mounting frame 14 to the arc-shaped contact groove 20 on the plane of the push plate 11 is H; then the first plane is translated by a distance of L, and the translated plane is used as the second plane, so that the second plane coincides with the sleeve axis; in the above, the center point P of the mounting frame 14 passes through the sleeve axis, that is, it is located in the second plane; the inner end surface of the closed end surface in the fixed position of the target ball fixing mechanism that is parallel to the sleeve axis is used as the first side surface of the fixed position of the target ball fixing mechanism; L=RD;

[0061] Step three, based on the second plane, establish a measurement coordinate system; the establishment of the measurement coordinate system is specifically as follows: the center point P of the mounting frame 14 is taken as the origin of the measurement coordinate system, the sleeve axis is the Z-axis direction of the measurement coordinate system, the positive direction of the Z-axis points to the expansion sleeve mechanism, the X-axis direction is the direction perpendicular to the second plane, the positive direction of the X-axis points to the first plane, and the Y-axis direction is determined according to the right-hand rule, that is, the measurement coordinate system O is completed. j -X j Y j Z j Then, the measurement coordinate system is translated H along the positive direction of the Z axis as a whole to obtain the drill bit coordinate system O tool -X tool Y tool Z tool ,like Fig.10 According to the position of the end of the drill bit 26 in the measurement coordinate system, the transformation relationship in the drill bit coordinate system is obtained is the translation vector and the rotation matrix Composition; Transformation relationship in drill bit coordinate system The expression is:

[0062]

[0063] In the formula, It can be obtained from SA software, using three points to fit the plane, offset, and get the homogeneous transformation matrix of the drill end; translation vector P0=[Px Py Pz] T -[L 0 0]T+[0 0 H] T , P0 represents the position of the end of the drill bit 26 in the measurement coordinate system, [Px Py Pz] represents the coordinates of P2 in the first plane; P = [Px Py Pz] T -[L 0 0] TIndicates the position of the center point P of the mounting frame 14 in the measurement coordinate system;

[0064] Step 4: Calibrate the industrial robot end flange coordinate system O f -X f Y f Z f The transformation relationship is the translation vector And the rotation matrix First, drive the industrial robot 29 to the zero position state, rotate the fifth joint of the industrial robot 29 slowly and steadily, and collect the position coordinates of the points at intervals of 2° (the rotation range of the robot joint is at least 60°), and then fit the above measurement points into a circle in the SA software, and use the normal vector of the circle as the five-axis axis, that is, the Z-axis direction of the base coordinate system of the industrial robot 29; similarly, adjust the industrial robot 29 to the zero position state again, rotate the sixth joint alone, rotate the sixth joint of the industrial robot 29 slowly and steadily, and collect the position coordinates of the points at intervals of 2° to obtain the six-axis axis of the industrial robot 29; then, use the SA software to find the common perpendicular line between the five-axis axis and the six-axis axis, that is, the X-axis of the coordinate system of the industrial robot terminal flange 27; then, cross multiply in the SA software to obtain the Y-axis direction of the coordinate system of the industrial robot terminal flange 27; finally, offset the length of the robot six-axis downward in the opposite direction of the Z-axis of the coordinate system of the robot terminal flange 27 as the origin of the coordinate system of the industrial robot terminal flange 27, thereby obtaining the coordinate system O of the industrial robot terminal flange 27 f -X f Y f Z f , and then we can get the transformation relationship

[0065] in:

[0066]

[0067] Step 5: According to and Obtain the position of the drill bit end is the translation vector And the rotation matrix

[0068]

[0069] According to the method and system for obtaining parameters of the end drill bit of an industrial robot of the above-mentioned embodiment of the present invention, by using the designed sleeve 30 in combination with the laser tracker 28 and the target ball 24, the position and posture of the end drill bit 26 of the robot can be effectively and directly obtained. This method replaces the traditional multi-point calibration method, and can greatly improve the position accuracy and posture accuracy of the end of the industrial robot 29. It also completes the acquisition of the end position of the robot more conveniently and quickly, providing a feasible method for subsequent calibration research. As an application environment of the method for obtaining the position and posture of the end drill bit 26 of an industrial robot of the embodiment of the present invention, such as Fig.11 shown.

[0070] The following is a description of an embodiment of removing the expansion sleeve mechanism:

[0071] Example 2: Figure 1-11 As shown, according to the first aspect of an embodiment of the present invention, a device for acquiring parameters of a drill bit at the end of an industrial robot is provided, comprising a sleeve 30, a reciprocating push rod mechanism, and a target ball fixing mechanism; in a usage mode in which the expansion sleeve mechanism is removed, one end of the reciprocating push rod mechanism extends into one end of the sleeve 30, and the target ball fixing mechanism is installed at one end of the reciprocating push rod mechanism extending out of the sleeve 30, and the other end of the sleeve 30 is used for the drill bit to extend into.

[0072] Furthermore, the reciprocating push rod mechanism includes a connecting rod 10, a push plate 11, and a movable snap-in device 17, and the industrial robot end drill bit parameter acquisition device also includes a grating ruler 25 installed on the inner side of a sleeve 30; one end of the push plate 11 is connected to one end of the connecting rod 10, and a target ball fixing mechanism is installed on the other end of the connecting rod 10; an arc-shaped contact groove 20 is provided at the other end of the push plate 11, and a movable snap-in device 17 is installed on the connecting rod 10; the connecting rod 10 is movably arranged in a first preset direction in the sleeve 30, and the arc-shaped contact groove 20 is brought into contact with the end of the drill bit by moving the connecting rod 10 along the first preset direction to read the information of the grating ruler 25.

[0073] Specifically, the method of using the expansion sleeve removal mechanism is as follows:

[0074] In this way, the expansion sleeve mechanism is removed, and the sleeve 30 is completely covered with the drill bit 26, so that the upper end surface of the sleeve 30 coincides with the end plane of the tool for mounting the drill bit 26, and the reciprocating push rod device is moved to make the end of the drill bit 26 completely contact with the arc-shaped contact groove 20, and the reading of the grating scale 25 is d3.

[0075] Furthermore, the movable buckle device 17 includes a spring mounting portion 21, a telescopic rod 22, and a spring 23; the sleeve 30 is provided with a plurality of fixed buckle holes arranged at intervals along a first preset direction; illustratively, Figure 7As shown, four fixing holes are shown, namely, the second fixing hole 13, the third fixing hole 15, the first fixing hole 12, and the fourth fixing hole 16 arranged in sequence from top to bottom; the spring mounting portion 21 is arranged on the connecting rod 10, and the two sides of the spring mounting portion 21 that are arranged opposite to each other and close to the inner side of the sleeve 30 are provided with grooves extending along the second preset direction, one end of the spring 23 is connected to the groove, and the other end of the spring 23 is connected to one end of the telescopic rod 22, and the other end of the telescopic rod 22 is a free end; the telescopic rod 22 is movably arranged along the second preset direction by the telescopic movement of the spring 23; the telescopic rod 22 is matched with the fixing hole at the desired position by the movement of the connecting rod 10 along the first preset direction.

[0076] Furthermore, the industrial robot end drill bit parameter acquisition device also includes:

[0077] A first guide structure 18, which is disposed inside the sleeve 30 and extends along a first preset direction, and is used to guide the movement of the telescopic rod 22 in the mobile buckle device 17 along the first preset direction;

[0078] The second guide structure 19 is arranged inside the sleeve 30 and extends along the first preset direction. The second guide structure 19 is used to guide the movement of the push plate 11 in the reciprocating push rod mechanism along the first preset direction. In specific applications, a protrusion is provided on the push plate 11, and the protrusion is slidably matched with the second guide structure 19 to guide the movement of the reciprocating push rod mechanism along the first preset direction.

[0079] Furthermore, the target ball fixing mechanism includes a mounting frame 14, a first target seat fixing position 1, a second target seat fixing position 7, a third target seat fixing position 8, and a fourth target seat fixing position 9; the first target seat fixing position 1, the second target seat fixing position 7, the third target seat fixing position 8, and the fourth target seat fixing position 9 are installed on the mounting frame 14 in an interval arrangement; the second target seat fixing position 7 and the fourth target seat fixing position 9 are symmetrically arranged based on the axial direction of the sleeve 30.

[0080] Exemplarily, the mounting frame 14 is cross-shaped and used to install four target seat fixing positions, wherein two target seat fixing positions are symmetrical based on the axis direction of the sleeve, thereby realizing position acquisition. The fixing position of the target ball fixing mechanism is a hollow cylindrical structure with an open upper end.

[0081] In specific applications, it can be used in conjunction with an industrial robot 29 and a laser tracker 28; the industrial robot 29 is a six-degree-of-freedom robot, the drill bit 26 is mounted on the end flange 27 of the industrial robot, and the end drill bit position acquisition device of the present invention is mounted on the drill bit 26, and used in the above two modes of use. In the first mode of use, after the sleeve 30 is fixed, the two target balls 24 are mounted on the second target seat fixing position 7 and the fourth target seat fixing position 9, and one target ball 24 is installed in one of the first target seat fixing position 1 or the third target seat fixing position 8. The above-described target ball 24 installation method can well achieve reasonable centering of the sleeve 30. The laser tracker 28 and the target ball 24 can cooperate to achieve the six-degree-of-freedom measurement of the end position of the industrial robot 29. Specifically, the laser emitted by the laser tracker 28 is on the corner cube prism of the target ball 24, and after reflection from the prism, the three-dimensional position of the target ball 24 can be measured, and the position information can be obtained by processing with the SA software.

[0082] According to a second aspect of an embodiment of the present invention, a method for obtaining parameters of an industrial robot end drill bit is provided, which is performed using the above-mentioned industrial robot end drill bit parameter obtaining device and is used for obtaining drill bit length parameters. Specifically, in this method, the expansion sleeve mechanism is removed, and the sleeve 30 is completely sleeved on the drill bit 26 so that the upper end surface of the sleeve 30 coincides with the tool end plane for installing the drill bit 26, and the reciprocating push rod device is moved so that the end of the drill bit 26 is completely in contact with the arc-shaped contact groove 20, and the reading of the grating scale 25 is d3.

[0083] Measuring the drill length with a grating ruler has the following advantages for industrial robots:

[0084] 1. The depth of drilling can be controlled (to know the drilling depth, the exposed length of the drill bit should be greater than the processing depth).

[0085] 2. The exposed length is suitable, which can facilitate cooling and chip removal (the exposed length affects the position where the coolant reaches the cutting edge and the discharge of chips. The appropriate exposed length helps cooling and chip removal).

[0086] 3. Prevent damage to the workpiece: Appropriate exposure length can prevent the drill bit from damaging the workpiece or the workbench below when penetrating the bottom of the workpiece.

[0087] 4. Prevent the drill bit from breaking: If the exposed length is too short, the drill bit may break due to excessive pressure; if the exposed length is too long, it may break due to imbalance during high-speed rotation.

[0088] The specific implementation modes of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A device for acquiring parameters of a drill bit at the end of an industrial robot, characterized in that: The device comprises a sleeve (30), a reciprocating push rod mechanism, and a target ball fixing mechanism; the industrial robot end drill bit parameter acquisition device realizes switching between two usage modes by attaching / removing an expansion sleeve mechanism; in the usage mode of attaching the expansion sleeve mechanism, one end of the reciprocating push rod mechanism extends into one end of the sleeve (30), the end of the reciprocating push rod mechanism extending out of the sleeve (30) is installed with the target ball fixing mechanism, and the expansion sleeve mechanism is installed at the other end of the sleeve (30) and the two cooperate to install the drill bit; in the usage mode of removing the expansion sleeve mechanism, one end of the reciprocating push rod mechanism extends into one end of the sleeve (30), the end of the reciprocating push rod mechanism extending out of the sleeve (30) is installed with the target ball fixing mechanism, and the other end of the sleeve (30) is used for the drill bit to extend into.

2. The industrial robot end drill bit parameter acquisition device according to claim 1, characterized in that: The expansion sleeve mechanism comprises an expansion sleeve outer sleeve (4), an expansion sleeve inner sleeve (5), a first screw (3) and a second screw (6); the expansion sleeve inner sleeve (5) extends into the expansion sleeve outer sleeve (4) and is fastened by the first screw (3) and the second screw (6).

3. The industrial robot end drill bit parameter acquisition device according to claim 1, characterized in that: The reciprocating push rod mechanism comprises a connecting rod (10), a push plate (11), and a movable snap-fit ​​device (17); the industrial robot end drill bit parameter acquisition device also comprises a grating ruler (25) installed on the inner side of a sleeve (30); one end of the push plate (11) is connected to one end of the connecting rod (10), and the other end of the connecting rod (10) is installed with a target ball fixing mechanism; the other end of the push plate (11) is provided with an arc-shaped contact groove (20), and the movable snap-fit ​​device (17) is installed on the connecting rod (10); the connecting rod (10) is movably arranged in a first preset direction in the sleeve (30), and the arc-shaped contact groove (20) is brought into contact with the end of the drill bit by the movement of the connecting rod (10) along the first preset direction, so as to read the information of the grating ruler (25).

4. The industrial robot end drill bit parameter acquisition device according to claim 3, characterized in that: The movable buckle device (17) comprises a spring mounting portion (21), a telescopic rod (22), and a spring (23); a plurality of fixed buckle holes arranged at intervals are provided on the sleeve (30) along a first preset direction; the spring mounting portion (21) is arranged on the connecting rod (10); two oppositely arranged sides of the spring mounting portion (21) close to the inner side of the sleeve (30) are provided with grooves extending along a second preset direction; one end of the spring (23) is connected to the groove, the other end of the spring (23) is connected to one end of the telescopic rod (22), and the other end of the telescopic rod (22) is a free end; the telescopic rod (22) is movably arranged along the second preset direction by the telescopic movement of the spring (23); and the telescopic rod (22) is matched with the fixed buckle hole at a desired position by the movement of the connecting rod (10) along the first preset direction.

5. The industrial robot end drill bit parameter acquisition device according to claim 1, characterized in that: The industrial robot end drill bit parameter acquisition device also includes: a first guide structure (18), the first guide structure (18) being arranged inside the sleeve (30) and extending along a first preset direction, the first guide structure (18) being used to guide the movement of the telescopic rod (22) in the movable buckle device (17) along the first preset direction; A second guide structure (19), wherein the second guide structure (19) is arranged inside the sleeve (30) and extends along a first preset direction, and the second guide structure (19) is used to guide the movement of the push plate (11) in the reciprocating push rod mechanism along the first preset direction.

6. The industrial robot end drill bit parameter acquisition device according to claim 1, characterized in that: The target ball fixing mechanism comprises a mounting frame (14), a first target seat fixing position (1), a second target seat fixing position (7), a third target seat fixing position (8), and a fourth target seat fixing position (9); the first target seat fixing position (1), the second target seat fixing position (7), the third target seat fixing position (8), and the fourth target seat fixing position (9) are installed on the mounting frame (14) in an interval arrangement; the second target seat fixing position (7) and the fourth target seat fixing position (9) are symmetrically arranged based on the axial direction of the sleeve (30).

7. A method for obtaining parameters of an industrial robot end drill bit, characterized in that: The industrial robot end drill bit parameter acquisition device according to any one of claims 1 to 6 is used to acquire the drill bit position and posture, and the acquisition steps are as follows: Step 1: fix the industrial robot end drill bit parameter acquisition device with an additional expansion sleeve mechanism on the industrial robot end drill bit (26), and install three target balls (24) on the target seat fixing position; put the laser tracker (28) on one side of the industrial robot, turn on the industrial robot, and put it in a normal working state; face the laser tracker (28) to the target seat fixing position in the target ball fixing mechanism, and make sure there is no obstacle between the laser tracker (28) and the target seat fixing position, and turn on the laser tracker (28) for preheating; Step 2, when the robot is in a zero position state, a laser tracker (28) is used to collect a point for each of the three target balls (24) installed on the target seat fixing position using SA software, that is, the target ball center coordinate positions are obtained as P1, P2, and P3 respectively, and a plane is fitted using these three points on the SA software as the first plane; it is known that in the design, the distance from the first side surface of the fixing position of the target ball fixing mechanism to the sleeve axis is D, the radius of the target ball is R, and the distance from the center point P of the mounting frame (14) to the arc-shaped contact groove (20) on the push plate (11) plane is H; then the first plane is translated by a distance L, and the translated plane is used as the second plane, so that the second plane coincides with the sleeve axis; wherein L=RD; Step three, based on the second plane, establish a measurement coordinate system; the establishment of the measurement coordinate system is specifically as follows: the center point P of the mounting frame (14) is taken as the origin of the measurement coordinate system, the sleeve axis is taken as the Z-axis direction of the measurement coordinate system, the positive direction of the Z-axis points to the expansion sleeve mechanism, the X-axis direction is the direction perpendicular to the second plane, the positive direction of the X-axis points to the first plane, and the Y-axis direction is determined according to the right-hand rule, thus completing the measurement coordinate system O. j -X j Y j Z j Establish; according to the position of the end of the drill bit (26) in the measurement coordinate system, obtain the transformation relationship in the drill bit coordinate system is the translation vector and the rotation matrix constitute; Step 4: Calibrate the industrial robot end flange coordinate system O f -X f Y f Z f The transformation relationship is the translation vector and the rotation matrix constitute; Step 5: According to and Obtain the position of the drill bit end 8. The method for obtaining parameters of an industrial robot end drill bit according to claim 7, characterized in that: The fixing position of the target ball fixing mechanism is a cylindrical structure with an open upper end and a hollow interior, and the inner end surface of the closed end surface in the fixing position of the target ball fixing mechanism which is parallel to the sleeve axis is used as the first side surface of the fixing position of the target ball fixing mechanism.

9. The method for obtaining parameters of an industrial robot end drill bit according to claim 7, characterized in that: The transformation relationship under the drill bit coordinate system The expression is: In the formula, the translation vector P0=[Px Py Pz] T -[L 0 0] T +[0 0 H] T , P0 represents the position of the end of the drill bit (26) in the measurement coordinate system, [Px Py Pz] represents the coordinates of P2 in the first plane; P = [Px Py Pz] T -[L 0 0] T Indicates the position of the center point P of the mounting frame (14) in the measurement coordinate system.

10. The method for obtaining parameters of an industrial robot end drill bit according to claim 7, characterized in that: The step 4 is specifically as follows: first, the industrial robot (29) is driven to a zero position state, the fifth joint of the industrial robot (29) is rotated, and the position coordinates of the points are collected at intervals of 2°, and then the above-mentioned measurement points are fitted into a circle in the SA software, and the normal vector of the circle is used as the five-axis axis, which is the Z-axis direction of the base coordinate system of the industrial robot (29); similarly, the industrial robot (29) is adjusted to a zero position state again, the sixth joint of the industrial robot (29) is rotated alone, and the position coordinates of the points are collected at intervals of 2° to obtain the six-axis axis of the industrial robot (29); then, the common perpendicular line between the five-axis axis and the six-axis axis is obtained by the SA software, which is the X-axis of the coordinate system of the industrial robot terminal flange (27); then, the Y-axis direction of the coordinate system of the industrial robot terminal flange (27) is obtained by cross multiplication in the SA software; finally, the length of the six-axis of the robot is offset downward in the opposite direction of the Z-axis of the coordinate system of the robot terminal flange (27) to be the origin of the coordinate system of the industrial robot terminal flange (27), thereby obtaining the coordinate system O of the industrial robot terminal flange (27) f -X f Y f Z f , and then we can get the transformation relationship

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