Underbody surface processing apparatus

Abstract

The application provides a fuselage lower surface processing equipment for polishing or spraying the lower surface of a fuselage, comprising an automatic guided vehicle, a processing executor, a parallel mechanism and a mechanical arm; the automatic guided vehicle can move along the XY plane; the processing executor is used for polishing / spraying the lower surface of the helicopter fuselage; the parallel mechanism is connected to the processing executor and is used for driving the processing executor to rotate along the X axis, rotate around the Y axis and move along the Z direction; one end of the mechanical arm is connected to the automatic guided vehicle, and the other end of the mechanical arm is connected to the parallel mechanism and is used for driving the processing executor to move along the X direction and move along the Y direction. The mechanical arm and the parallel mechanism with redundant degrees of freedom are linked to solve the problems of large-range movement, full-range coverage and posture adjustment of the processing executor under the restriction of a narrow space, realize automatic polishing and spraying of the lower surface of the helicopter fuselage, and improve the quality and efficiency of polishing and spraying.

Description

Technical Field

[0001] This invention relates to the field of digital manufacturing and assembly technology for helicopters, and more specifically, to a machine for processing the lower surface of a fuselage. Background Technology

[0002] Currently, automated grinding and painting equipment is used for fixed-wing aircraft. Due to the large size of the landing gear structure, the space between the lower surface of the fuselage and the ground after the landing gear supports the aircraft is sufficient to accommodate conventional automated grinding and painting equipment, meeting its operational requirements. However, the landing gear of rotorcraft, such as helicopters, is generally divided into skid-type and wheeled types. The smaller size of the landing gear results in a shorter distance between the lower surface of the helicopter fuselage and the ground, and the relatively large area of ​​the lower surface creates a large, narrow space between the helicopter fuselage and the ground. Existing industrial robots, with their large size, cannot fit into this narrow space. Furthermore, the characteristics of robot motion dictate that multiple axes (even all six axes) need to move together to achieve end-effector motion. Sometimes, even small-range movements of the end-effector require large-range movements from individual axes. Therefore, the narrow space cannot meet the motion requirements of industrial robots. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] The technical problem to be solved by this invention is how to achieve automatic grinding and spraying of the lower surface of a helicopter fuselage in a confined space.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a fuselage under-surface processing device for grinding or spraying the under-surface of a helicopter fuselage. The device includes an automated guided vehicle (AGV), a processing actuator, a parallel mechanism, and a robotic arm. The AAV is capable of moving along the XY plane. The processing actuator is used to grind / spray the under-surface of the helicopter fuselage. The parallel mechanism is connected to the processing actuator and drives it to rotate along the X-axis, rotate around the Y-axis, and move along the Z-axis. One end of the robotic arm is connected to the AAV, and the other end is connected to the parallel mechanism, driving the processing actuator to move along the X-axis and along the Y-axis.

[0008] Preferably, the robotic arm includes a first joint assembly, a first link assembly, a second joint assembly, a second link assembly, a third joint assembly, and a third link assembly. The first joint assembly is connected to the automated guided vehicle. One end of the first link assembly is rotatably connected to the first joint assembly, and the other end of the first link assembly is rotatably connected to the second joint assembly. One end of the second link assembly is connected to the second joint assembly, and the other end of the second link assembly is connected to the third joint assembly. One end of the third link assembly is connected to the third joint assembly, and the other end of the third link assembly is connected to the machining actuator.

[0009] Preferably, the first joint assembly includes a support, a first motor, a first bearing, and a first pressure cap. The output end of the first motor is connected to the first pressure cap, the first pressure cap is fixedly connected to the support, the outer ring of the first bearing is connected to the support, the inner ring of the first bearing is connected to the housing of the first motor, and the support is connected to the first connecting rod assembly.

[0010] Preferably, the second joint assembly includes a front support, a rear support, a second motor, a second bearing, and a second pressure cap. The front support is connected to the housing of the second motor, the output shaft of the second motor is fixedly connected to the second pressure cap, the second pressure cap is connected to the rear support, the outer ring of the second bearing is connected to the rear support, the inner ring of the second bearing is connected to the housing of the second motor, the front support is connected to the first connecting rod assembly, and the rear support is connected to the second connecting rod assembly.

[0011] Preferably, the automated guided vehicle includes a body and a plurality of Mecanum wheels, the Mecanum wheels being located at the bottom of the body.

[0012] Preferably, the parallel mechanism includes a fixed platform assembly, a moving platform assembly, three connecting rods, and three sliding pairs. The three connecting rods and the three sliding pairs are connected one-to-one. One end of each connecting rod is hinged to the moving platform assembly, and the other end of each connecting rod is rotatably connected to the corresponding sliding pair. Each sliding pair is slidably connected to the fixed platform assembly.

[0013] Preferably, the sliding pair includes a lead screw assembly and a slider. The lead screw assembly is disposed on the fixed platform assembly, and the slider is threadedly connected to the lead screw assembly. The lead screw assembly can drive the slider to move.

[0014] Preferably, the machining equipment for the lower surface of the fuselage satisfies the following dimensional constraints:

[0015]

[0016]

[0017]

[0018] In the formula, aB 1 represents the distance between the flange axis of the first linkage assembly and the upper plane of the automated guided vehicle. a This is the proportionality coefficient. H A The distance between the upper surface of the automated guided vehicle and the ground. h L This is the distance between the lowest point of the robotic arm and the ground. l 1 represents the length of the first link assembly. α 1 represents the angle between the axis of the first link assembly and the ground. l 2 represents the length of the second link assembly. α 2 represents the angle between the axis of the second linkage assembly and the ground. l 3 represents the length of the third link assembly. α 3 represents the angle between the axis of the third link assembly and the ground. r Let the radius of the first link assembly be . H The height between the lower surface of the fuselage and the ground. h 2D The height between the grinding end of the machining actuator and the ground. h 1max The maximum height that the parallel mechanism can move along the Z-axis. h 1min Δ is the minimum height that the parallel mechanism needs to move along the Z direction. d This is to maintain a safe distance between the spraying actuator end of the machining actuator and the lower surface of the machine body. h 3 represents the bending height of the third link assembly. h 2P The height between the spraying end of the machining actuator and the ground.

[0019] Preferably, the machining equipment for the lower surface of the fuselage satisfies the following torque constraint relationship:

[0020]

[0021] In the formula, G L1 The force of gravity acting on the first link assembly, G L2 The gravity acting on the second link assembly, G L3 The force of gravity acting on the third link assembly. G 2 represents the gravity acting on the second joint assembly. G 3 represents the gravity acting on the third joint assembly. L1 represents the distance between the first joint assembly and the second joint assembly. L 2 represents the distance between the second and third joint components. L 3 represents the distance between the centers of the third joint assembly and the connection point between the third joint assembly and the parallel mechanism. G B The force of gravity acting on the parallel mechanism, G T The force of gravity acting on the machining actuator. G A The force of gravity acting on the automated guided vehicle. L A The distance between the center of mass of the automated guided vehicle and the axis of the first joint assembly is denoted as . τ For safety factor and .

[0022] Preferably, the machining equipment for the lower surface of the fuselage satisfies the following angular constraints:

[0023]

[0024] In the formula, θ 1 represents the joint angle of the first joint assembly. θ 2 represents the joint angle of the second joint assembly. θ 3 represents the joint angle of the third joint component. θ r1 This represents the maximum range of rotation of the joint angle of the first joint assembly. θ r2 This represents the maximum range of rotation for the joint angle of the second joint assembly. θ r3 This represents the maximum range of rotation for the joint angle of the third joint component.

[0025] (III) Beneficial Effects

[0026] The above-described technical solution of the present invention has at least the following advantages:

[0027] This invention solves the problems of large-scale movement, full-range coverage, and attitude adjustment of processing actuators under confined space constraints by using a robotic arm with redundant degrees of freedom and a parallel mechanism, thus realizing automated grinding and painting of the lower surface of a helicopter fuselage. It avoids the potential dangers of manual operation and the risk of product damage, improving the quality and efficiency of grinding and painting. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a diagram showing the usage status of the fuselage lower surface processing equipment provided in this embodiment of the invention.

[0030] Figure 2 This is a schematic diagram of the structure of the fuselage lower surface processing equipment provided in an embodiment of the present invention.

[0031] Figure 3 This is a schematic diagram of the degrees of freedom of the fuselage lower surface processing equipment provided in an embodiment of the present invention.

[0032] Figure 4 This is one of the main view annotations of the fuselage lower surface processing equipment provided in the embodiments of the present invention.

[0033] Figure 5 This is the second front view annotation of the fuselage lower surface processing equipment provided in the embodiment of the present invention.

[0034] Figure 6 This is a diagram showing the usage status of the fuselage lower surface processing equipment provided in this embodiment of the invention.

[0035] Figure 7 This is a schematic diagram of the structure of the automated guided vehicle provided in an embodiment of the present invention.

[0036] Figure 8 This is a schematic diagram of the structure of the robotic arm provided in an embodiment of the present invention.

[0037] Figure 9 This is a schematic diagram of the structure of the first joint assembly provided in an embodiment of the present invention.

[0038] Figure 10 This is a schematic diagram of the structure of the first link assembly provided in an embodiment of the present invention.

[0039] Figure 11 This is a cross-sectional view of the first link assembly provided in an embodiment of the present invention.

[0040] Figure 12 This is a schematic diagram of the structure of the second link assembly provided in an embodiment of the present invention.

[0041] Figure 13 This is a cross-sectional view of the second link assembly provided in an embodiment of the present invention.

[0042] Figure 14 This is a schematic diagram of the structure of the third link assembly provided in an embodiment of the present invention.

[0043] Figure 15 This is a cross-sectional view of the third link assembly provided in an embodiment of the present invention.

[0044] Figure 16 This is a schematic diagram of the structure of the second joint assembly provided in an embodiment of the present invention.

[0045] Figure 17 This is a schematic diagram of the design principle of the parallel mechanism provided in the embodiment of the present invention.

[0046] Figure 18 This is a schematic diagram of the parallel mechanism provided in an embodiment of the present invention.

[0047] Figure 19 This is a schematic diagram of the structure of the moving platform provided in an embodiment of the present invention.

[0048] Figure 20 This is a schematic diagram of the connecting rod provided in an embodiment of the present invention.

[0049] Figure 21 This is a schematic diagram of the structure of the lead screw nut provided in an embodiment of the present invention.

[0050] Figure 22 This is a schematic diagram of the fixed platform provided in an embodiment of the present invention.

[0051] Figure 23 This is a schematic diagram of the structure of the first lead screw assembly provided in an embodiment of the present invention.

[0052] The labels for the attached figures are as follows:

[0053] 11. Automated Guided Vehicle (AGV); 12. Robotic Arm; 13. Parallel Mechanism; 14. Machining Actuator; 111. Vehicle Body; 112. Mecanum Wheel; 121. First Joint Assembly; 122. First Link Assembly; 123. Second Joint Assembly; 124. Second Link Assembly; 125. Third Joint Assembly; 126. Third Link Assembly; 1211. First Screw; 1212. Support; 1213. Second Screw; 1214. First Pressure Cap; 1215. Third Screw; 1216. First Motor Housing; 1217. First Tapered Roller Bearing; 218. Bearing spacer; 1219. Second tapered roller bearing; 12110. First motor; 1221. Fourth screw; 1222. First connecting rod; 1223. Fifth screw; 1231. Support base; 1232. First support; 1233. Front support; 1234. Second support; 1235. Twelfth screw; 1236. Second gland; 1237. Eleventh screw; 1238. Bearing cover plate; 1239. Tenth screw; 12310. Third tapered roller bearing; 12311. Second motor housing; 12312. Collar; 12313, Fourth tapered roller bearing; 12314, Second motor; 1241, Sixth screw; 1242, Second connecting rod; 1243, Seventh screw; 1261, Eighth screw; 1262, Third connecting rod; 1263, Ninth screw; 131, Moving platform assembly; 132, First connecting rod; 133, Second connecting rod; 134, Third connecting rod; 135, First slider; 136, Second slider; 137, Third slider; 138, Fixed platform assembly; 1311, Moving platform; 1312, Thirteenth screw; 1313, First ball joint Support; 1314, Second ball joint support; 1315, Third ball joint support; 1351, Pin; 1352, Leadscrew nut; 1381, First leadscrew assembly; 1382, Second leadscrew assembly; 1383, Third leadscrew assembly; 13811, Leadscrew support seat; 13812, Fourteenth screw; 13813, Fifteenth screw; 13814, First bearing cap; 13815, Second bearing cap; 13816, First deep groove ball bearing; 13817, Leadscrew; 13818, Sixteenth screw; 13819, Second deep groove ball bearing. Detailed Implementation

[0054] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0055] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be located directly on or indirectly on the other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to the other component.

[0056] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate that the device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or the number of technical features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. The specific implementation of this invention will be described in more detail below with reference to specific embodiments:

[0058] like Figure 1 , Figure 2 and Figure 3 As shown in the figure, an embodiment of the present invention provides a fuselage lower surface processing device for grinding or spraying the lower surface of a helicopter fuselage 2. The device includes an automated guided vehicle 11, a robotic arm 12, a parallel mechanism 13, and a processing actuator 14. The automated guided vehicle 11 is capable of moving along the XY plane. The processing actuator 14 is used for grinding / spraying the lower surface of the helicopter fuselage. The parallel mechanism 13 is connected to the processing actuator 14 and is used to drive the processing actuator 14 to rotate along the X-axis, rotate around the Y-axis, and move along the Z-axis. One end of the robotic arm 12 is connected to the automated guided vehicle 11, and the other end of the robotic arm 12 is connected to the parallel mechanism 13, used to drive the processing actuator 14 to move along the X-axis and along the Y-axis.

[0059] like Figure 8As shown, in one embodiment, the robotic arm 12 includes a first joint assembly 121, a first link assembly 122, a second joint assembly 123, a second link assembly 124, a third joint assembly 125, and a third link assembly 126. The first joint assembly 121 is connected to the automated guided vehicle 11. One end of the first link assembly 122 is rotatably connected to the first joint assembly 121, and the other end of the first link assembly 122 is rotatably connected to the second joint assembly 123. One end of the second link assembly 124 is connected to the second joint assembly 123, and the other end of the second link assembly 124 is connected to the third joint assembly 125. One end of the third link assembly 126 is connected to the third joint assembly 125, and the other end of the third link assembly 126 is connected to the processing actuator 14.

[0060] like Figure 8 and Figure 9As shown, in one embodiment, the first joint assembly 121 includes a support 1212, a first motor 12110, a first bearing (including a first tapered roller bearing 1217 and a second tapered roller bearing 1219), and a first pressure cap 1214. The output end of the first motor 12110 is connected to the first pressure cap 1214, the first pressure cap 1214 is fixedly connected to the support 1212, the outer ring of the first bearing is connected to the support 1212, and the inner ring of the first bearing is connected to the housing of the first motor (first motor housing 1216). The support 1212 is connected to the first connecting rod assembly 122. Preferably, the first motor 12110 is a harmonic reducer. Harmonic reducers have advantages such as simplicity and compactness, small size, light weight, large transmission ratio range, high load capacity, high transmission accuracy, high efficiency, smooth movement, and convenient differential transmission, making them suitable as drive motors for robotic arm joints. The harmonic reducer is installed inside the first motor housing 1216. One end of the first motor housing 1216 has an output flange, through which power is transmitted. The first joint assembly 121 is fixed to the automated guided vehicle 11 via a first screw 1211. A first tapered roller bearing 1217 is installed on the first motor housing 1216 and is axially positioned by a shoulder on the first motor housing 1216. A second tapered roller bearing 1219 is installed on the first motor housing 1216 near the output end of the first motor 12110. The first tapered roller bearing 1217 and the second tapered roller bearing 1219 are separated by a bearing spacer 1218, which fits against the outer ring end face of the first tapered roller bearing 1217 and the outer ring end face of the second tapered roller bearing 1219. The support 1212 is mounted on the outer ring of the first tapered roller bearing 1217, the outer ring of the second tapered roller bearing 1219, and the bearing spacer. The threaded hole on the support is used to connect with the first connecting rod assembly 122. The first pressure cap 1214 is connected to the support 1212 via a second screw 1213 and to the output flange of the first motor 12110 via a third screw 1215. When energized, the first motor 12110 transmits torque to the first pressure cap 1214 through the output flange. The first pressure cap 1214 drives the support 1212 to rotate, which in turn drives the first connecting rod assembly 122 to rotate. During this process, the inner rings of the first tapered roller bearing 1217 and the second tapered roller bearing 1219 remain stationary, while their outer rings rotate with the support 1212.

[0061] like Figure 10 and Figure 11As shown, specifically, the first connecting rod assembly 122 includes a fourth screw 1221, a first connecting rod 1222, and a fifth screw 1223. A first flange and a second flange are respectively provided at both ends of the first connecting rod 1222. The first flange is connected to the first joint assembly 121 via the fourth screw 1221, and the second flange is connected to the second joint assembly 123 via the fifth screw 1223. An angle exists between the axis of the first connecting rod 1222 and the axes of the first and second flanges. α 1. Defined as the inclination angle of the first link 1222, which allows the first link assembly 122 to tilt towards the ground after being assembled onto the first joint assembly 121. The vertical distance between the first flange and the second flange is used as the length design dimension of the first link 1222. l 1.

[0062] like Figure 12 and Figure 13 As shown, the second link assembly 124 further includes a sixth screw 1241, a second link 1242, and a seventh screw 1243. The second link 1242 has a third flange and a fourth flange at its two ends, respectively. The third flange is connected to the third joint assembly 125 via the sixth screw 1241, and the fourth flange is connected to the second joint assembly 123 via the seventh screw 1243. The angle between the axis of the second link 1242 and the axes of the third and fourth flanges is... α 2 is the design tilt angle of the second connecting rod assembly 124, and the vertical distance between the outer end faces of the two flanges is taken as the length design dimension l2 of the connecting rod 1242.

[0063] like Figure 14 and Figure 15 As shown, further, the third link assembly 126 consists of an eighth screw 1261, a third link 1262, and a ninth screw 1263. One end of the third link 1262 has a bent section, with a fifth flange at the end of the bent section. The other end of the third link 1262 has a sixth flange. The fifth flange is connected to the parallel mechanism 13 via the eighth screw 1261. The bent design ensures that the fixed platform 1334 of the parallel mechanism 13 is always parallel to the ground. The sixth flange is connected to the third joint assembly 125 via the ninth screw 1263, and the angle between its axis and the axis of the third link 1262 is [insert angle here]. α 3. The bending angle is 90°, and the axis of the fifth flange is perpendicular to the axis of the sixth flange. The minimum distance from the axis of the fifth flange to the outer end face of the sixth flange is used as the design dimension for the length of the third connecting rod 1262. l 3. The distance from the upper end face of the fifth flange to the axis of the sixth flange is used as the design dimension for the bending height. h 3.

[0064] like Figure 8and Figure 16 As shown, in one embodiment, the second joint assembly 123 includes a front support 1233, a rear support, a second motor 12314, a second bearing (including a third tapered roller bearing 12310 and a fourth tapered roller bearing 12313), and a second pressure cap 1236. The rear support includes a first support 1232, a second support 1234, and a support base 1231. The support base 1231 connects the first support 1232 and the second support 1234. The front support 1233 is connected to the housing of the second motor (second motor housing 12311). The output shaft of the second motor 12314 is fixedly connected to the second pressure cap 1236. The second pressure cap 1236 is connected to the rear support. The outer ring of the second bearing is connected to the rear support, and the inner ring of the second bearing is connected to the housing of the second motor. The front support 1233 is connected to the first connecting rod assembly 122, and the rear support is connected to the second connecting rod assembly 124. Specifically, the front support 1233 is interference-fitted with the second motor housing 12311 to connect the first connecting rod assembly 122, and is axially positioned by a collar on the second motor housing 12311. A collar 12312 and a fourth tapered roller bearing 12313 are sequentially installed on the second motor housing 12311 from the end face of the front support 1233 to the output end of the second motor 12314, with the end face of the collar 12312 fitting against the inner ring end face of the fourth tapered roller bearing 12313. A third tapered roller bearing 12310 is installed at the other end of the second motor housing 12311 and is axially positioned by a collar. The first support 1232 and the second support 1234 are respectively mounted on the outer rings of the third tapered roller bearing 12310 and the fourth tapered roller bearing 12313. The first support 1232 and the second support 1234 are connected to the support base 1231 to form a whole. The other side of the support base 1231 has a threaded hole for connecting the second connecting rod assembly 124. The bearing cover plate 1238 is connected to the first support 1232 by the tenth screw 1239 for fixing and protecting the third tapered roller bearing 12310. The second pressure cover 1236 is connected to the output flange of the second motor 12314 by the eleventh screw 1237, and the twelfth screw 1235 is used to connect the second pressure cover 1236 and the second support 1234. The second motor 12314 transmits torque to the second pressure plate 1236 through the output flange. The second pressure plate 1236 drives the second support 1234, support base 1231, first support 1232 and bearing cover 1238 to rotate relative to the front support 1233, that is, the second connecting rod assembly 124 rotates relative to the first connecting rod assembly 122.

[0065] like Figure 7 As shown, in one embodiment, the automated guided vehicle 11 includes a body 111 and a plurality of Mecanum wheels 112 located at the bottom of the body 111.

[0066] like Figure 17 and Figure 18 As shown, in one embodiment, the parallel mechanism 13 includes a fixed platform assembly 138, a moving platform assembly 131, three connecting rods (a first connecting rod 132, a second connecting rod 133, and a third connecting rod 134, respectively), and three sliding pairs. The three connecting rods and the three sliding pairs are connected one-to-one. One end of each connecting rod is hinged to the moving platform assembly 131, and the other end of each connecting rod is rotatably connected to the corresponding sliding pair. Each sliding pair is slidably connected to the fixed platform assembly 138. Specifically, the fixed platform assembly 138 is connected to the fifth flange of the third link assembly. The first connecting rod 132, the second connecting rod 133, and the third connecting rod 134 are arranged in a triangle on the fixed platform assembly 138. The moving platform assembly 131 is connected to the three connecting rods via ball joints. Specifically, the linear motion unit used to form the sliding pairs is a ball screw mechanism, which has advantages such as high precision, high transmission efficiency, low friction, and smooth movement.

[0067] like Figure 19 and Figure 20 As shown, more specifically, the moving platform assembly 131 consists of a moving platform 1311, a thirteenth screw 1312, a first ball joint support 1313, a second ball joint support 1314, and a third ball joint support 1315. The first ball joint support 1313, the second ball joint support 1314, and the third ball joint support 1315 are respectively fixed to the moving platform 1311 by the thirteenth screw 1312. A threaded hole is provided on the other side of the moving platform 1311 for connecting a machining actuator. The first connecting rod 132, the second connecting rod 133, and the third connecting rod 134 have the same structure. Taking the first connecting rod 132 as an example, one end of the first connecting rod 132 is designed as a ball head, which is connected to the first ball joint support 1313 of the moving platform assembly 131 to form a ball joint. The ball head can rotate around any axis of the first ball joint support 1313, realizing the three-dimensional movement of the moving platform 1311. The other end is rotatably connected to the third slider 137 to form a revolute joint.

[0068] like Figure 21 , Figure 22 as well as Figure 23As shown, in one embodiment, the sliding pair includes a lead screw assembly and a slider. The lead screw assembly is mounted on the fixed platform assembly 138, and the slider is threadedly connected to the lead screw assembly. The lead screw assembly can drive the slider to move. Specifically, there are three lead screw assemblies: a first lead screw assembly 1381, a second lead screw assembly 1382, and a third lead screw assembly 1383. The first lead screw assembly 1381, the second lead screw assembly 1382, and the third lead screw assembly 1383 have the same structure. Taking the first lead screw assembly 1381 as an example, the first lead screw assembly 1381 consists of a lead screw support 13811, a fourteenth screw 13812, a fifteenth screw 13813, a first bearing cap 13814, a second bearing cap 13815, a first deep groove ball bearing 13816, a lead screw 13817, a sixteenth screw 13818, and a second deep groove ball bearing 13819. The lead screw support 13811 is fixed to the fixed platform 1334 by the fourteenth screw 13812. A first deep groove ball bearing 13816, a second deep groove ball bearing 13819, and a thrust ring are installed at both ends of the lead screw 13817, all within the lead screw support 13811. A second bearing cap 13815 is connected to the lead screw support 13811 by the sixteenth screw 13818, protecting the second deep groove ball bearing 13819. A first bearing cap 13814 is connected to the lead screw support 13811 by the fifteenth screw 13813, protecting the first deep groove ball bearing 13816. A hole is drilled in the center of the first bearing cap 13814 to connect the lead screw 13817 to the coupling and the lead screw motor. Driven by the lead screw motor, the lead screw 13817 rotates. The lead screw nut 1352, driven by the balls, converts the rotational motion of the lead screw into linear motion, forming a sliding pair. There are three sliders: slider 135, slider 136, and slider 137. Slider 135, slider 136, and slider 137 have the same structure. Taking slider 135 as an example, slider 135 consists of a pin 1351 and a lead screw nut 1352. Pin 1351 connects the lead screw nut 1352 and the third connecting rod 134, forming a rotating pair. After the lead screw nut 1352 is assembled with the lead screw 13817, a helical raceway is formed. Balls roll within the raceway, and the rotational motion of the lead screw 13817 is converted into the linear motion of the lead screw nut 1352 using the friction and torque transmission principle of the threaded pair.

[0069] like Figure 4 As shown, in one embodiment, the machining equipment for the lower surface of the fuselage satisfies the following dimensional constraints:

[0070] (1)

[0071] (2)

[0072] (3)

[0073] In the formula, aB 1 represents the distance between the flange axis of the first linkage assembly and the upper plane of the automated guided vehicle. a This is the proportionality coefficient. H A The distance between the upper surface of the automated guided vehicle and the ground. h L This is the distance between the lowest point of the robotic arm and the ground. l 1 represents the length of the first link assembly. α 1 represents the angle between the axis of the first link assembly and the ground. l 2 represents the length of the second link assembly. α 2 represents the angle between the axis of the second linkage assembly and the ground. l 3 represents the length of the third link assembly. α 3 represents the angle between the axis of the third link assembly and the ground. r Let the radius of the first link assembly be . H The height between the lower surface of the fuselage and the ground. h 2D The height between the grinding end of the machining actuator and the ground. h 1max The maximum height that the parallel mechanism can move along the Z-axis. h 1min Δ is the minimum height that the parallel mechanism needs to move along the Z direction. d This is to maintain a safe distance between the spraying actuator end of the machining actuator and the lower surface of the machine body. h 3 represents the bending height of the third link assembly. h 2P This refers to the height between the spraying actuator end of the machining actuator and the ground. Specifically, the tilt angles of each link of the robotic arm decrease sequentially, thus satisfying... Equation (1) is to ensure that the lowest point of the robotic arm's linkage does not touch the ground during the movement of the automated guided vehicle, in order to prevent uneven ground or obstacles from obstructing the movement of the robotic arm. Grinding and spraying processes are different, and the heights of the grinding actuator and the spraying actuator are different, so the requirements for the space under the machine body are also different. When performing grinding operations, the grinding actuator is required to contact the lower surface of the machine body, so equation (2) needs to be satisfied. When performing spraying operations, the spraying actuator is required to maintain a safe distance Δd from the lower surface of the machine body, so each parameter needs to satisfy equation (3).

[0074] like Figure 5As shown, in one embodiment, to prevent the equipment from tipping over, in addition to satisfying dimensional constraints, torque constraints must also be satisfied. When the distance from the end to the flange axis of the automated guided vehicle reaches its maximum, that is, when the axes of all connecting rods are coplanar and the robotic arm is in a "straightened" state, the torque acting on the connection between the robotic arm and the automated guided vehicle reaches its maximum value. At this time, all parameters must satisfy equation (4). The machining equipment on the lower surface of the fuselage satisfies the following torque constraint relationship:

[0075] (4)

[0076] In the formula, G L1 The force of gravity acting on the first link assembly, G L2 The gravity acting on the second link assembly, G L3 The force of gravity acting on the third link assembly. G 2 represents the gravity acting on the second joint assembly. G 3 represents the gravity acting on the third joint assembly. L 1 represents the distance between the first joint assembly and the second joint assembly. L 2 represents the distance between the second and third joint components. L 3 represents the distance between the centers of the third joint assembly and the connection point between the third joint assembly and the parallel mechanism. G B The force of gravity acting on the parallel mechanism, G T The force of gravity acting on the machining actuator. G A The force of gravity acting on the automated guided vehicle. L A The distance between the center of mass of the automated guided vehicle and the axis of the first joint assembly is denoted as . τ For safety factor and The safety factor is used to compensate for calculation errors caused by deviations in the selection of the centroid of the robotic arm, parallel mechanisms, and machining actuators.

[0077] like Figure 6 As shown, in one embodiment, the machining equipment for the lower surface of the fuselage satisfies the following angular constraint relationship:

[0078] (5)

[0079] In the formula, θ 1 represents the joint angle of the first joint assembly. θ 2 represents the joint angle of the second joint assembly. θ 3 represents the joint angle of the third joint component. θ r1This represents the maximum range of rotation of the joint angle of the first joint assembly. θ r2 This represents the maximum range of rotation for the joint angle of the second joint assembly. θ r3 This represents the maximum rotational range of the joint angle of the third joint component. In the global coordinate system... O G -X G Y G Inside, The dashed rectangle enclosed by the four points represents the working area of ​​the machining actuator 14, the solid rectangle represents the outline of the automated guided vehicle 11, O1, O2, and O3 are the center points of the first joint assembly 121, the second joint assembly 123, and the third joint assembly 125, and point P is the working center point of the machining actuator 14. The end effector of the robotic arm 12 must completely cover the working area, i.e., the coordinates of point P in the global coordinate system... To take every point within the rectangular dashed frame, it can be expressed as the following formula (6).

[0080] (6)

[0081] Local coordinate systems are established with the center points of the first joint assembly 121, the second joint assembly 123, and the third joint assembly 125 as the origin and the 0° direction of the joint angle as the positive X-axis. O 1 -X 1 Y 1. O 2 -X 2 Y 2. O 3 -X 3 Y 3. Coordinate system of the actuator center relative to the first joint assembly 121 O 1 -X 1 Y The positional relationship of 1 can be represented by vector equation (7):

[0082] (7)

[0083] Based on the motion transmission relationship, determine the transformation relationship between each local coordinate system and the coordinate system. O 1 -X 1 Y By understanding the transformation relationship between 1 and the global coordinate system, the position of P in the global coordinate system can be determined. First joint component 121 coordinate system. O 1 -X 1 Y 1. With the global coordinate systemO G -X G Y G The transformation relationship can be expressed using a homogeneous transformation matrix. express:

[0084] (8)

[0085] In the formula θ 0 is the coordinate system O 1 -X 1 Y 1. Relative to the coordinate system O G -X G Y G rotation angle, Point O1 in the global coordinate system O G -X G Y G The coordinates in the coordinate system of the first joint component 121. O 1 -X 1 Y Coordinate system of 1 and the second joint assembly 123 O 2 -X 2 Y The transformation relationship of 2 is expressed using a homogeneous transformation matrix. Represented as:

[0086] (9)

[0087] In the formula θ 12 Indicates when θ Coordinate system when 1=0 O 2 -X 2 Y 2. Relative to the coordinate system O 1 -X 1 Y Rotation angle of 1. Coordinate system of the second joint assembly 123. O 2 -X 2 Y 2 and the coordinate system of the third joint assembly 125 O 3 -X 3 Y The transformation relationship of 3 is expressed using a homogeneous transformation matrix. Represented as:

[0088] (10)

[0089] In the formula θ 23 Indicates when θ Coordinate system when 2=0 O 3- X 3 Y 3. Relative to the coordinate system O 2- X 2 Y Rotation angle of 2. From the global coordinate system. O G - X G Y G Coordinate system to the third joint assembly 125 O 3- X 3 Y The transformation relationship of 3 is expressed using a matrix. Represented as:

[0090] (11)

[0091] In the formula:

[0092] , , ,

[0093] , ,

[0094] .

[0095] Center point of machining actuator 14 P In the coordinate system of the third joint assembly 125 O 3- X 3 Y The coordinates in 3 are Calculated by equation (12) P In the global coordinate system O G - X G Y G coordinates in

[0096] (12)

[0097] Substitute the calculation results into equation (5) to determine the rotation range of each joint angle.

[0098] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A machine body lower surface processing device, used for grinding or spraying the lower surface of a machine body, characterized in that, include: Automated guided vehicles are capable of moving along the XY plane; Machining actuators are used for grinding or spraying the lower surface of helicopter fuselage; A parallel mechanism is connected to the machining actuator and is used to drive the machining actuator to rotate along the X-axis, rotate about the Y-axis, and move along the Z-axis; A robotic arm, with one end connected to the automated guided vehicle and the other end connected to the parallel mechanism, is used to drive the machining actuator to move along the X-axis and along the Y-axis. The robotic arm includes a first joint assembly, a first link assembly, a second joint assembly, a second link assembly, a third joint assembly, and a third link assembly. The first joint assembly is connected to the automated guided vehicle. One end of the first link assembly is rotatably connected to the first joint assembly, and the other end of the first link assembly is rotatably connected to the second joint assembly. One end of the second link assembly is connected to the second joint assembly, and the other end of the second link assembly is connected to the third joint assembly. One end of the third link assembly is connected to the third joint assembly, and the other end of the third link assembly is connected to the machining actuator. The machining equipment for the lower surface of the fuselage satisfies the following dimensional constraints: In the formula, aB 1 represents the distance between the flange axis of the first linkage assembly and the upper plane of the automated guided vehicle. a This is the proportionality coefficient. H A The distance between the upper surface of the automated guided vehicle and the ground. h L This is the distance between the lowest point of the robotic arm and the ground. l 1 represents the length of the first link assembly. α 1 represents the angle between the axis of the first link assembly and the ground. l 2 represents the length of the second link assembly. α 2 represents the angle between the axis of the second linkage assembly and the ground. l 3 represents the length of the third link assembly. α 3 represents the angle between the axis of the third link assembly and the ground. r Let the radius of the first link assembly be . H The height between the lower surface of the fuselage and the ground. h 2D The height between the grinding end of the machining actuator and the ground. h 1max The maximum height that the parallel mechanism can move along the Z-axis. h 1min Δ is the minimum height that the parallel mechanism needs to move along the Z direction. d This is to maintain a safe distance between the spraying actuator end of the machining actuator and the lower surface of the machine body. h 3 represents the bending height of the third link assembly. h 2P The height between the spraying end of the machining actuator and the ground.

2. The fuselage lower surface processing equipment as described in claim 1, characterized in that, The first joint assembly includes a support, a first motor, a first bearing, and a first pressure cap. The output end of the first motor is connected to the first pressure cap, the first pressure cap is fixedly connected to the support, the outer ring of the first bearing is connected to the support, the inner ring of the first bearing is connected to the housing of the first motor, and the support is connected to the first connecting rod assembly.

3. The fuselage lower surface processing equipment as described in claim 1, characterized in that, The second joint assembly includes a front support, a rear support, a second motor, a second bearing, and a second pressure cap. The front support is connected to the housing of the second motor, the output shaft of the second motor is fixedly connected to the second pressure cap, the second pressure cap is connected to the rear support, the outer ring of the second bearing is connected to the rear support, the inner ring of the second bearing is connected to the housing of the second motor, the front support is connected to the first connecting rod assembly, and the rear support is connected to the second connecting rod assembly.

4. The fuselage lower surface processing equipment as described in claim 1, characterized in that, The automated guided vehicle includes a body and a plurality of Mecanum wheels, the Mecanum wheels being located at the bottom of the body.

5. The fuselage lower surface processing equipment as described in claim 1, characterized in that, The parallel mechanism includes a fixed platform assembly, a moving platform assembly, three connecting rods, and three sliding pairs. The three connecting rods and the three sliding pairs are connected one-to-one. One end of each connecting rod is hinged to the moving platform assembly, and the other end of each connecting rod is rotatably connected to the corresponding sliding pair. Each sliding pair is slidably connected to the fixed platform assembly.

6. The fuselage lower surface processing equipment as described in claim 5, characterized in that, The sliding pair includes a lead screw assembly and a slider. The lead screw assembly is disposed on the fixed platform assembly, and the slider is threadedly connected to the lead screw assembly. The lead screw assembly can drive the slider to move.

7. The fuselage lower surface processing equipment as described in claim 1, characterized in that, The machining equipment for the lower surface of the fuselage satisfies the following torque constraint relationship: In the formula, G L1 The force of gravity acting on the first link assembly, G L2 The gravity acting on the second link assembly, G L3 The force of gravity acting on the third link assembly. G 2 represents the gravity acting on the second joint assembly. G 3 represents the gravity acting on the third joint assembly. L 1 represents the distance between the first joint assembly and the second joint assembly. L 2 represents the distance between the second and third joint components. L 3 represents the distance between the centers of the third joint assembly and the connection point between the third joint assembly and the parallel mechanism. G B The force of gravity acting on the parallel mechanism, G T The force of gravity acting on the machining actuator. G A The force of gravity acting on the automated guided vehicle. L A The distance between the center of mass of the automated guided vehicle and the axis of the first joint assembly is denoted as . τ For safety factor and .

8. The fuselage lower surface processing equipment as described in claim 1, characterized in that, The machining equipment for the lower surface of the fuselage satisfies the following angular constraints: In the formula, θ1 is the joint angle of the first joint assembly, θ2 is the joint angle of the second joint assembly, θ3 is the joint angle of the third joint assembly, and θ r1 θ represents the maximum range of rotation of the joint angle of the first joint assembly. r2 θ represents the maximum range of rotation of the joint angle of the second joint assembly. r3 This represents the maximum range of rotation for the joint angle of the third joint component.

Images