Diesel engine assembling system and control method thereof

Abstract

The invention provides a diesel engine assembling system and a control method thereof, and belongs to the technical field of diesel engine core component assembling. The diesel engine assembling system comprises a six-dimensional moving platform and a working platform; the working platform is fixedly mounted below the six-dimensional moving platform, and an end effector used for clamping engine parts is fixedly mounted at the bottom of the six-dimensional moving platform; the six-dimensional moving platform comprises a horizontal direction shaft, a vertical direction shaft and a front-back direction shaft; the number of the shafts in the vertical direction is four, and the number of the shafts in the horizontal direction is two. A horizontal shaft is mounted between the two vertical shafts in a sliding manner; the front-back direction shaft is slidably mounted on the horizontal direction shaft through a connecting block; a connecting circular truncated cone is slidably mounted below the front-back direction shaft through a connecting block; a vertical rotating shaft is fixedly mounted on the connecting circular truncated cone; and a horizontal front-back rotating shaft is fixedly mounted below the vertical rotating shaft.

Description

Technical Field

[0001] The present invention belongs to the technical field of diesel engine core component assembly, and in particular, relates to a diesel engine assembly system and a control method thereof. Background Art

[0002] Compared with other internal combustion engines, diesel engines are widely used in national production because of their large torque, high thermal efficiency and good economic performance.

[0003] When the engine is working, the inner surface of the cylinder liner, its core component, is in direct contact with high-temperature combustion gas. Its temperature and pressure change frequently, and its instantaneous value is very high, which imposes a large thermal and mechanical load on the cylinder. The piston makes high-speed reciprocating linear motion in the cylinder, and the inner wall of the cylinder plays a guiding role. The main function of the cylinder head is to seal the cylinder, form a combustion space together with the piston, and withstand the action of high-temperature and high-pressure combustion gas. It is located on the top of the cylinder body, seals the cylinder from the top and forms a combustion chamber, so it bears a large thermal and mechanical load.

[0004] At present, the conventional assembly solutions in the diesel engine industry are: Experienced operators assemble the different parts of the diesel engine in sequence according to the technical requirements of the operation instructions. For example, the cylinder head assembly requires horizontal assembly without gaps around it; the piston assembly requirements and the concentricity of the cylinder liner, etc.

[0005] With the improvement of automation level, robots are gradually replacing manual work. Pre-programmed assembly robots can identify and grasp diesel engine parts, replace manual work, simulate the actions of operators, perform operations such as moving, flipping, and inserting, and realize assembly on the assembly line.

[0006] Analysis of the existing technology reveals the following problems: Problem 1: Manual assembly has poor consistency and unstable quality. The assembly of diesel engines requires high-precision processing and assembly technology, which requires high skills of operators. If the operator's technical level is insufficient, it may cause errors in the assembly process, affecting the performance and reliability of the engine; in addition, the instability of the working state of the personnel, such as fatigue and mistakes, will also make the quality of the assembly work unstable.

[0007] Problem 2: Conventional robot assembly often has slight deviations in position and angle, which can cause the piston to be stuck in the cylinder liner and even break the piston ring in severe cases. Sometimes these more demanding assemblies have to be handled manually, which results in poor consistency and unstable quality. Summary of the invention

[0008] In view of this, the present invention proposes a diesel engine assembly system and a control method thereof to solve the problems of poor consistency and unstable quality in current manual assembly; it can also solve the problem of cumulative precision errors in continuous operation of the robotic arm and the increase of errors over time; and it can also solve the problem of combined errors in multi-axis linkage.

[0009] The present invention provides a diesel engine assembly system, which includes a six-dimensional mobile platform and a working platform; the working platform is fixedly installed below the six-dimensional mobile platform, and an end effector for clamping engine parts is fixedly installed at the bottom of the six-dimensional mobile platform; The six-dimensional mobile platform includes a horizontal axis, a vertical axis, and a front-to-back axis; there are four vertical axes and two horizontal axes; a horizontal axis is slidably installed between the two vertical axes; the front-to-back axis is slidably installed on the horizontal axis through a connecting block; a connecting round table is slidably installed below the front-to-back axis through a connecting block; a vertical rotation axis is fixedly installed on the connecting round table; a horizontal front-to-back rotation axis is rotatably installed below the vertical rotation axis; An end effector is fixedly installed at the bottom of the horizontal front-to-back rotation axis, and a gyroscope is installed inside the end effector; the working platform is located below the end effector; a downward-looking camera and a downward-looking laser rangefinder are also fixedly installed below the connecting truncated table; an upward-looking camera and an upward-looking laser rangefinder are also fixedly installed on the upper surface of the working platform.

[0010] On the basis of the above technical solution, the diesel engine assembly system proposed by the present invention can also be improved as follows: Furthermore, the horizontal and front-to-back rotation axes are two angle tables.

[0011] Furthermore, the horizontal front and rear rotation axes are combined into a hexapod displacement platform.

[0012] The present invention proposes a control method for a diesel engine assembly system, wherein the main body of the assembly system is a six-dimensional mobile platform, the six-dimensional mobile platform has X, Y, Z, U, V1, W1 axes, realizes six degrees of freedom of movement, and automatically completes the diesel engine component assembly process, specifically including the following steps: S1 automatic calibration eliminates cumulative errors. After the six-dimensional mobile platform has been running for a period of time, there will be cumulative errors in accuracy. Through automatic calibration, the cumulative errors of orthogonality of the X and Y axes and the cumulative errors of verticality of the Z axis can be eliminated. S2 automatically levels the reference plane of the assembled parts, using the gyroscope and the original Z-axis assembly relationship to ensure that the reference plane of the assembled parts is horizontal. At this time, there is a horizontal and vertical correspondence between the assembled parts, the assembling parts and the Z-axis. The assembly action can be simplified into a single-axis vertical assembly action in the Z direction. The fewer the number of axes, the higher the accuracy. The vertical assembly action in the Z direction alone will not have deviations in the X and Y directions; S3 obtains the X, Y, Z coordinate values ​​and U angle coordinate value of the assembled part on the workbench, and uses vision and sensing to obtain the coordinate values ​​of the position of the assembled part on the workbench plane; S4 automatically adjusts the reference plane of the assembly on the six-dimensional mobile platform to the horizontal level; S5 obtains the X, Y, Z coordinate values ​​and U angle coordinate value of the assembly on the six-dimensional mobile platform, and uses vision and sensing to obtain the coordinate values ​​of the position of the assembly component on the plane of the six-dimensional mobile platform; The upper and lower parts of S6 are first fitted and then assembled. The assembly path is determined based on the trial results and the assembly is finally completed.

[0013] Further, the process of eliminating the Z-axis cumulative error in step S1 includes: S11 Z-axis calibration: Use the top-down camera and the auxiliary nine-square diagram to calculate the pixel deviation value, and feed the deviation value back to the Z-axis deviation compensation program to complete the calibration in the Z-axis direction; S12 X and Y axis calibration: Use the top-down camera, auxiliary nine-square diagram and the gyroscope inside the end effector to calculate the deviation value of the end effector in the X and Y axis directions, and import the deviation value into the six-dimensional mobile platform, and use the deviation compensation system to calibrate the deviation in the X and Y axis directions; S13Z-axis deviation calibration, X-axis deviation calibration and Y-axis deviation calibration are all performed during loading and unloading of the assembly system.

[0014] Furthermore, leveling the reference plane of the assembled parts in step S2 specifically includes: Adjust the absolute verticality of the Z-axis direction of the reference plane of the assembled parts, use the laser rangefinder and the gyroscope in the end effector to calculate the inclination angles of W and V, and adjust the assembled reference plane to the horizontal according to the angle feedback.

[0015] Furthermore, the specific steps of obtaining the coordinate values ​​of the assembled parts in step S3 include: S31 obtains the X and Y coordinate values ​​of the assembled part: using the overhead camera, the gyroscope and the cross mark 1 on the upper left corner of the assembled part reference plane, obtains the coordinates of the assembled part at the corresponding mark position, and obtains the camera pixel coordinates at the corresponding position, and calculates the mechanical size of each pixel point; combining the distance from the camera coordinate zero point to the center of the mobile platform and the coordinates of the overhead camera position, calculates the coordinate position of the assembled part in the X and Y directions in the world coordinate system of the six-dimensional mobile platform; S32 obtains the coordinate value of the assembled component in the Z direction in the world coordinate system of the six-dimensional mobile platform: using the overhead camera and the gyroscope, in conjunction with the cross mark 1 in the upper left corner and the cross mark 2 in the lower right corner of the reference plane of the assembled component, the coordinate position of the assembled component in the Z direction in the world coordinate system of the six-dimensional mobile platform is calculated according to the corresponding center position coordinates.

[0016] Further, the specific steps of adjusting the assembly to a horizontal level in step S4 are as follows: In conjunction with the upward laser rangefinder and the assembly reference plane, the inclination angles of the W and V axes of the assembly are calculated. The six-dimensional mobile platform adjusts the W and V axis motors according to the inclination angle compensation to achieve horizontal assembly.

[0017] Furthermore, the specific steps of obtaining the coordinate values ​​of the assembly in the world coordinate system of the six-dimensional mobile platform in step S5 are as follows: S51 obtains the X and Y coordinate values ​​of the assembly in the world coordinate system of the six-dimensional mobile platform: uses the upward camera, the gyroscope and the cross mark three on the upper left corner of the assembly reference plane to obtain the coordinates of the assembly at the corresponding mark position, and obtains the camera pixel coordinates of the corresponding position based on this, and calculates the mechanical size of each pixel point; combines the distance from the camera coordinate zero point to the center of the mobile platform and the upward camera position coordinates to calculate the coordinate position of the assembly in the X and Y directions in the world coordinate system of the six-dimensional mobile platform; S52 obtains the coordinate value of the assembly in the Z direction in the world coordinate system of the six-dimensional mobile platform: using the upward-looking camera and the gyroscope, in conjunction with the cross mark three in the upper left corner and the cross mark four in the lower right corner of the assembly reference plane, the coordinate position of the assembly in the Z direction in the world coordinate system of the six-dimensional mobile platform is calculated according to the corresponding center position coordinates.

[0018] Further, the assembly process in step S6 specifically includes the following steps: S61 completes the fitting of the world coordinate system of the assembled component and the origin of the world coordinate system of the assembling component; S62 completes the fitting of the world coordinate system of the assembled component and the X-axis and Y-axis of the world coordinate system of the assembling component; S63 completes the fitting of the world coordinate system of the assembled component and the Z axis and U axis of the world coordinate system of the assembling component; S64 corrects the corresponding coordinates based on the fitting data and completes the assembly using a six-dimensional mobile platform.

[0019] Compared with the prior art, the diesel engine assembly system and control method provided by the present invention have the following beneficial effects: When assembling mechanical parts, a slight tilt of the assembly surface can lead to quality defects. The present invention has an automatic plane leveling function, uses laser ranging to test the multi-point distances between the two assembly surfaces of the assembling component and the assembled component, calculates the V coordinate value and W coordinate value of each plane tilt angle, and ensures the consistency of assembly flatness through the movement of the mechanical arm and the workbench.

[0020] The present invention pre-adjusts the arm posture before assembly, and only has a Z-axis vertical single-axis assembly during assembly, thereby avoiding combination errors caused by multi-axis linkage. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the first embodiment; Figure 2 is a schematic diagram of the overall structure of the second embodiment; Figure 3 To eliminate the Z-axis cumulative error process top view; Figure 4 To obtain the top view of the coordinate process of the assembled parts; Figure 5 To obtain the coordinate process of the assembly, a bottom view is provided; Figure 6 is a method flow chart; In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Horizontal axis; 2. Vertical axis; 3. Front and rear axis; 4. Connecting round table; 41. Downward looking camera; 42. Downward laser rangefinder; 5. Connecting block; 6. Corner table; 7. Hexapod displacement platform; 8. Working platform; 81. Upward-looking camera; 82. Upward-looking laser rangefinder; 9. Vertical rotation axis. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] A diesel engine assembly system of the present invention comprises a six-dimensional mobile platform and a working platform 8; the working platform 8 is fixedly installed below the six-dimensional mobile platform, and an end effector for clamping engine parts is fixedly installed at the bottom of the six-dimensional mobile platform; The six-dimensional mobile platform includes a horizontal axis 1, a vertical axis 2 and a front-to-back axis 3; there are four vertical axes 2 and two horizontal axes 1; a horizontal axis 1 is slidably installed between the two vertical axes 2, and the two horizontal axes 1 are parallel; the front-to-back axis 3 is slidably installed on the horizontal axis 1 through a connecting block 5 in the horizontal direction; a connecting round table 4 is slidably installed in the front-to-back direction below the front-to-back axis 3 through a connecting block 5; a vertical rotation axis 9 is fixedly installed on the connecting round table 4; a horizontal front-to-back rotation axis is rotatably installed below the vertical rotation axis 9; An end effector is fixedly installed at the bottom of the horizontal front-to-back rotation axis, and a gyroscope is installed inside the end effector; the working platform 8 is located below the end effector; a downward-looking camera 41 and a downward-looking laser rangefinder 42 are also fixedly installed below the connecting truncated table 4; an upward-looking camera 81 and an upward-looking laser rangefinder 82 are also fixedly installed on the upper surface of the working platform 8.

[0024] Optional, such as Figure 1 As shown, it is the first embodiment of the present invention. In the above technical solution, the horizontal front-to-back direction rotation axis is a combination of two angle tables 6.

[0025] Optional, such as Figure 2 As shown, it is a second embodiment of the present invention. In the above technical solution, the horizontal front-to-back direction rotation axis is a hexapod displacement platform 7.

[0026] like Figure 3-6 As shown, a control method of a diesel engine assembly system provided by the present invention includes an assembly system having X, Y, Z, U, V1, and W1 axes to achieve six degrees of freedom of motion, wherein the six degrees of freedom are defined as: X degree of freedom of movement: the degree of freedom of movement of an object in the x-axis direction; Y degree of freedom: the degree of freedom of movement of an object in the y-axis direction; Z degree of freedom: the degree of freedom of movement of an object in the z-axis direction; U rotational freedom: the rotational freedom of an object around the z-axis; V1 rotational freedom: the rotational freedom of the object with the y-axis as the axis; W1 rotational freedom: the rotational freedom of the object around the x-axis; The automatic assembly process of diesel engine components specifically includes the following steps: S1 automatic calibration eliminates cumulative errors. After the six-dimensional mobile platform has been running for a period of time, there will be cumulative errors in accuracy. Through automatic calibration, the cumulative errors of orthogonality of the XY axis and the cumulative errors of verticality of the Z axis can be eliminated. S2 automatically levels the reference plane of the assembled parts, using the gyroscope and the original Z-axis assembly relationship to ensure that the reference plane of the assembled parts is horizontal. At this time, there is a horizontal and vertical correspondence between the reference plane of the assembled parts, the assembled parts and the assembled parts. The assembly action can be simplified into a single-axis vertical assembly action in the Z direction. The fewer the number of axes, the higher the accuracy. The vertical assembly action in the Z direction alone will not have deviations in the XY directions; S3 obtains the XYZ coordinate values ​​and U angle coordinate values ​​of the assembled parts on the workbench, and uses vision and sensing to obtain the coordinate values ​​of the position of the assembled parts on the workbench plane; S4 automatically adjusts the reference plane of the assembly on the six-dimensional mobile platform to the horizontal level; S5 obtains the XYZ coordinate values ​​and U angle coordinate values ​​of the assembly parts on the six-axis six-dimensional mobile platform, and uses vision and sensing to obtain the coordinate values ​​of the positions of the assembly parts on the plane of the six-dimensional mobile platform; The upper and lower parts of S6 are first fitted and then assembled. The assembly path is determined based on the trial results and the assembly is finally completed.

[0027] Optionally, in the above technical solution, the process of eliminating the Z-axis cumulative error in step S1 includes: S11 Z-axis direction calibration: The end actuator of the six-dimensional mobile platform drives the top-down camera 41 to move to the highest position along the Z axis, and automatically moves to the top of the No. 1 mark of the nine-square diagram, and automatically adjusts the cross center of the top-down camera 41 lens and the cross center of the nine-square diagram point to align, with a deviation of 0.1 pixel points; the end actuator of the six-dimensional mobile platform vertically falls along the Z axis and moves to the lowest position, and the top-down camera 41 calculates the pixel deviation (x1, y1) between the cross center of the top-down camera 41 lens and the cross center of the nine-square diagram point; S12 repeats step S11 to obtain the pixel point deviations (x2, y2), (x3, y3), (x4, y4), (x5, y5), (x6, y6), (x7, y7), (x8, y8), (x9, y9) of the cross center of the overhead camera 41 lens and the cross center of the nine-square icon point at the lowest point of the Z axis of the remaining eight marked points, and obtain the average value (xf, yf) of the above data group, and import (xf, yf) into the robot Z axis deviation compensation program to correct the deviation of the Z axis verticality; The process of eliminating the accumulated errors of the X and Y axes in step S1 includes: The end actuator of the S13 six-dimensional mobile platform drives the top-view camera 41 to automatically move to the nine-square when the Z axis moves to the highest position. Figure 1Above the dot, record the current end effector coordinate value (rx1, ry1) and the current pixel coordinate value (px1, py1); Use the same method to record the end effector coordinate values ​​(rx2, ry2), (rx3, ry3), (rx4, ry4), (rx5, ry5), (rx6, ry6), (rx7, ry7), (rx8, ry8), (rx9, ry9) and pixel coordinate values ​​(px2, py2), (px3, py3), (px4, py4), (px5, py5), (px6, py6), (px7, py7), (px8, py8), (px9, py9) at the remaining 8 mark positions; Calculate the average value of the end effector coordinate value (rxf, ryf) and the average value of the pixel coordinate value (pxf, pyf) respectively; The above average values ​​(rxf, ryf) and (pxf, pyf) are introduced into the robot arm X and Y axis deviation compensation program to correct the deviation of the orthogonality of the X and Y axes; The above XYZ automatic calibration steps are performed in parallel during loading and unloading of the device.

[0028] Optionally, in the above technical solution, leveling the reference plane of the assembled parts in step S2 specifically includes: S21 The assembled part is placed on the workbench. There is a horizontal and vertical correspondence between the reference plane of the assembled part and the assembly process. The fewer the number of axes, the higher the accuracy. The vertical assembly action in the Z direction alone does not have deviation in the XY direction. Therefore, the adjustment process only needs to ensure the vertical state of Z and the horizontality of the reference plane of the assembled part. The end actuator of the six-dimensional mobile platform drives the downward laser rangefinder 42 to detect the height distances d1, d2, d3, and d4 of the four vertices of the reference plane of the assembled component. Assuming that the horizontal spacing of the four vertices is row1 and the vertical spacing is column1, the W and V axis inclination angles dw1 and dv1 are calculated: dw1=arctan(((d2-d1)+(d3-d4)) / 2column1), dw2=arctan(((d4-d1)+(d3-d2)) / 2row1); According to the W and V axis tilt angles dw1 and dv1, the W and V axis motors on the workbench adjust the reference plane of the assembled parts to a horizontal state.

[0029] Optionally, in the above technical solution, in step S3, the specific steps of obtaining the coordinate values ​​are as follows: S31 obtains the XY coordinate values ​​of the components to be assembled on the workbench: the assembled component is placed on the workbench, the reference plane of the assembled component has been adjusted to be horizontal after step S2, and a cross mark 1 is set at the upper left corner of the reference plane of the assembled component. The top-view camera (41) is moved three positions under the drive of the six-dimensional mobile platform, so that the cross mark 1 at the upper left corner of the reference plane of the assembled component is respectively located at the upper left corner position, the upper right corner position, and the lower left corner position of the field of view of the top-view camera (41), which respectively correspond to the world coordinates (jx1, jy1), (jx2, jy2), (jx3, jy3) of the six-dimensional mobile platform, and respectively correspond to the camera pixel coordinates (jpx1, jpy1), (jpx2, jpy2), (jpx3, jpy3), and calculate the mechanical size of each pixel point of the camera; The distance from the camera pixel coordinate zero point to the center point of the actuator of the end fixture of the six-dimensional mobile platform is recorded as (gx1, gy1), the coordinates of the camera position of the six-dimensional mobile platform are (sx1, sy1), and the pixel coordinates of the assembled part in the camera field of view are (tx1, ty1). Based on this, the coordinate position of the assembled part in the world coordinate system of the mobile platform is calculated; S32 obtains the Z coordinate value of the assembled part on the workbench: the assembled part is placed on the workbench, and the reference plane of the assembled part has been adjusted to be horizontal after step S2. The overhead camera 41 moves under the drive of the six-dimensional mobile platform so that the cross mark 1 at the upper left corner of the reference plane of the assembled part is located at the center of the field of view of the overhead camera 41, and the pixel coordinates are obtained as (ax1, ay1); the cross mark 2 at the lower right corner of the reference plane of the assembled part is located at the center of the field of view of the overhead camera (41), and the pixel coordinates are obtained as (ax2, ay2), and the pixel coordinates are calculated according to the center position coordinate values.

[0030] Optionally, in the above technical solution, in step S4, the specific steps of adjusting the assembly to be horizontal are as follows: The assembly is grabbed by the six-dimensional mobile platform and moved upward. The laser rangefinder 82 detects the height distances b1, b2, b3, and b4 of the four vertices of the assembly reference plane. The horizontal spacing of the four vertices is row2, and the vertical spacing is column2. The W and V axis tilt angles dw2 and dv2 are calculated: dw2=arctan(((b2-b1)+(b3-b4)) / 2column2), dw2=arctan(((b4-b1)+(b3-b2)) / 2row2); After the data is input, the six-dimensional mobile platform adjusts the W and V axis motors according to the tilt angle compensation and adjusts the assembly reference plane to a horizontal state.

[0031] Optionally, in the above technical solution, in step S5, the specific steps of obtaining the coordinate values ​​are as follows: S51 obtains the XY coordinate values ​​of the assembly on the six-dimensional mobile platform: the assembly is driven by the six-dimensional mobile platform and moves to three positions within the field of view of the upward camera 81, so that the three cross marks on the upper left corner of the assembly reference plane are respectively located at the upper left corner, upper right corner and lower left corner of the field of view of the upward camera 81, which correspond to the world coordinates (jrx1, jry1), (jrx2, jry2), (jrx3, jry3) of the six-dimensional mobile platform, and the pixel coordinates (jqx1, jqy1), (jqx2, jqy2), (jqx3, jqy3) of the camera, respectively. According to the world coordinates and pixel coordinates, the mechanical size of each pixel of the camera is calculated: (cx,cy)=((jrx2-jrx1) / (jqx2-jqx1), (jrx3-jrx1) / (jqx3-jqx1)); The distance from the camera pixel coordinate zero point to the center point of the actuator of the end fixture of the six-dimensional mobile platform is (gx2, gy2), the camera position coordinates of the six-dimensional mobile platform are (sx2, sy2), and the pixel coordinates of the assembly in the camera field of view are (tx2, ty2). The coordinate position of the assembly in the world coordinate system of the mobile platform is calculated as follows: (Mx,My)=(gx2+((jrx2-jrx1) / (jqx2-jqx1))tx2+sx2,gy2+((jrx3-jrx1) / (jqx3-jqx1))ty2+sy2); S52 obtains the Z coordinate value of the assembly on the six-dimensional mobile platform; based on the assembly reference plane and the upward laser rangefinder 82, obtains the Z coordinate value of the assembly on the six-dimensional mobile platform; S53 obtains the U coordinate value of the assembly on the six-dimensional mobile platform: driven by the six-dimensional mobile platform, the assembly enters the field of view of the upward camera 81, so that the cross mark three in the upper left corner of the assembly reference plane is located at the center of the field of view of the upward camera 81, and the pixel coordinates are obtained as (ax3, ay3); the cross mark in the lower right corner of the assembly reference plane is located at the center of the field of view of the upward camera 81, and the pixel coordinates are obtained as (ax4, ay4). The angle U coordinate value of the assembly component is calculated according to the center position coordinate value: Uangle=arctan{(ay4-ay3) / (ax4-ax3)}.

[0032] Optionally, in the above technical solution, the assembly process in step S6 specifically includes the following steps: S61 completes the fitting of the world coordinate system of the assembled component and the origin of the world coordinate system of the assembling component; S62 completes the fitting of the world coordinate system of the assembled component and the X-axis and Y-axis of the world coordinate system of the assembling component; The X and Y coordinates that the six-dimensional mobile platform needs to move are: (X, Y) = (X2-X1, Y2-Y1); S63 completes the fitting of the world coordinate system of the assembled component and the Z axis and U axis of the world coordinate system of the assembling component; There is an angle deviation between the two coordinate systems, so the coordinates after fitting are: (X', Y') = (xcosθ + ysinθ, ycosθ - xsinθ), where θ is the offset angle between the two coordinate systems, and θ = U2 - U1; S64 corrects the corresponding coordinates based on the fitting data and completes the assembly using a six-dimensional mobile platform; Corrected coordinate values: (X, Y, Z, U, V, W) = ((X2-X1)cosθ+(Y2-Y1)sinθ, (Y2-Y1)cosθ-(X2-X1)sinθ, (Z2-Z1), (U2-U1), 0, 0).

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A diesel engine assembly system, comprising a six-dimensional mobile platform and a working platform (8); the working platform (8) is fixedly installed below the six-dimensional mobile platform, and an end effector for clamping engine parts is fixedly installed at the bottom of the six-dimensional mobile platform; It is characterized in that The six-dimensional mobile platform comprises a horizontal axis (1), a vertical axis (2), and a front-to-back axis (3); there are four vertical axes (2) and two horizontal axes (1); a horizontal axis (1) is slidably mounted between the two vertical axes (2); the front-to-back axis (3) is slidably mounted on the horizontal axis (1) via a connecting block (5); a connecting truncated platform (4) is slidably mounted below the front-to-back axis (3) via a connecting block (5); a vertical rotation axis (9) is fixedly mounted on the connecting truncated platform (4); a horizontal front-to-back rotation axis is rotatably mounted below the vertical rotation axis (9); An end effector is fixedly mounted at the bottom of the horizontal front-to-back rotation axis, and a gyroscope is installed inside the end effector; the working platform (8) is located below the end effector; a downward-looking camera (41) and a downward-facing laser rangefinder (42) are also fixedly mounted below the connecting truncated table (4); and an upward-looking camera (81) and an upward-facing laser rangefinder (82) are also fixedly mounted on the upper surface of the working platform (8).

2. A diesel engine assembly system according to claim 1, characterized in that: The horizontal front-to-back direction rotation axes are two angle tables (6).

3. A diesel engine assembly system according to claim 1, characterized in that: The horizontal front-to-back rotation axis is a hexapod displacement platform (7).

4. A control method for a diesel engine assembly system, wherein the main body of the assembly system is a six-dimensional mobile platform, and the six-dimensional mobile platform has six degrees of freedom of motion: X, Y, Z, U, V1, and W1, characterized in that: The control method is applicable to a diesel engine assembly system according to any one of claims 1 to 3, and the diesel engine component assembly process specifically includes the following steps: S1: Automatic calibration to eliminate cumulative errors. After the six-dimensional mobile platform has been running for a period of time, there will be cumulative errors in accuracy. Through automatic calibration, the cumulative errors of orthogonality of the XY axis and the cumulative errors of verticality of the Z axis can be eliminated. S2: Automatically level the reference plane of the assembled parts, using the gyroscope and the assembly relationship with the original Z axis to ensure that the reference plane of the assembled parts is horizontal. At this time, there is a horizontal and vertical correspondence between the reference plane of the assembled parts, the assembly parts and the Z axis. The assembly action can be simplified into a single-axis vertical assembly action in the Z direction. The fewer the number of axes, the higher the accuracy. The vertical assembly action in the Z direction alone will not have deviations in the XY directions; S3: Obtain the XYZ coordinate values ​​and U angle coordinate values ​​of the assembled parts on the workbench, and use vision and sensing to obtain the coordinate values ​​of the position of the assembled parts on the workbench plane; S4: Automatically adjust the reference plane of the assembly on the six-dimensional mobile platform to be horizontal; S5: Obtain the XYZ coordinate value and U angle coordinate value of the assembly on the six-dimensional mobile platform, and use vision and sensing to obtain the coordinate value of the position of the assembly in the world coordinate system of the six-dimensional mobile platform; S6: The coordinates of the assembling part and the assembled part are determined to be the same except for the coordinate in the Z direction, and then the assembly path is determined to finally complete the assembly.

5. A control method for a diesel engine assembly system according to claim 4, characterized in that: The process of eliminating the Z-axis cumulative error in step S1 includes: S11: Z-axis direction calibration: using the top-view camera (41) and the auxiliary nine-square diagram, the pixel deviation value is calculated, and the deviation value is fed back to the Z-axis deviation compensation program to complete the calibration in the Z-axis direction; S12: X-axis and Y-axis direction calibration: using the top-view camera (41), the auxiliary nine-square diagram and the gyroscope inside the end effector, the deviation values ​​of the end effector in the X-axis and Y-axis directions are calculated, and the deviation values ​​are imported into the six-dimensional mobile platform, and the deviation compensation system is used to calibrate the deviations in the X-axis and Y-axis directions; S13: Z-axis deviation calibration, X-axis deviation calibration and Y-axis deviation calibration are all performed during loading and unloading of the assembly system.

6. The control method of a diesel engine assembly system according to claim 4, characterized in that: Leveling the reference plane of the assembled parts in step S2 specifically includes: S21: Adjust the absolute verticality of the Z-axis direction of the reference plane of the assembled parts, calculate the tilt angles of W and V using the downward laser rangefinder (42) and the gyroscope in the end effector, and adjust the assembled reference plane to the horizontal according to the angle feedback.

7. The control method of a diesel engine assembly system according to claim 4, characterized in that: The specific steps for obtaining the coordinate values ​​in step S3 include: S31: Obtaining the X and Y coordinate values ​​of the assembled component: using the overhead camera (41), the gyroscope and the cross mark 1 on the upper left corner of the assembled component reference plane, obtaining the coordinates of the assembled component at the corresponding marked position, thereby obtaining the camera pixel coordinates at the corresponding position, and calculating the mechanical size of each pixel point; combining the distance from the camera coordinate zero point to the center of the mobile platform and the position coordinates of the overhead camera (41), calculating the coordinate position of the assembled component in the X and Y directions in the world coordinate system of the six-dimensional mobile platform; S32: Obtain the coordinate value of the assembled component in the Z direction in the world coordinate system of the six-dimensional mobile platform: Utilize the overhead camera (41) and the gyroscope, in conjunction with the cross mark 1 at the upper left corner and the cross mark 2 at the lower right corner of the reference plane of the assembled component, and calculate the coordinate position of the assembled component in the Z direction in the world coordinate system of the six-dimensional mobile platform according to the corresponding center position coordinates.

8. The control method of a diesel engine assembly system according to claim 4, characterized in that: The specific steps of adjusting the assembly to be horizontal in step S4 are as follows: cooperate with the upward laser rangefinder (82) and the assembly reference plane to calculate the inclination angle of the W and V axes of the assembly, and the six-dimensional mobile platform adjusts the W and V axis motors according to the inclination angle compensation to achieve the assembly to be horizontal.

9. The control method of a diesel engine assembly system according to claim 4, characterized in that: The specific steps for obtaining the coordinate values ​​of the assembly parts in the world coordinate system of the six-dimensional mobile platform in step S5 are as follows: S51: Obtain the X and Y coordinate values ​​of the assembly in the world coordinate system of the six-dimensional mobile platform: use the upward camera (81), the gyroscope and the cross mark three on the upper left corner of the assembly reference plane to obtain the coordinates of the assembly at the corresponding marked position, and obtain the camera pixel coordinates at the corresponding position based on this, and calculate the mechanical size of each pixel point; combine the distance from the camera coordinate zero point to the center of the mobile platform and the position coordinates of the upward camera (81) to calculate the coordinate position of the assembly in the X and Y directions in the world coordinate system of the six-dimensional mobile platform; S52: Obtain the coordinate value of the assembly in the Z direction in the world coordinate system of the six-dimensional mobile platform: Utilize the upward-looking camera (81) and the gyroscope, cooperate with the cross mark three at the upper left corner and the cross mark four at the lower right corner of the assembly reference plane, and calculate the coordinate position of the assembly in the Z direction in the world coordinate system of the six-dimensional mobile platform according to the corresponding center position coordinates.

10. A control method for a diesel engine assembly system according to claim 9, characterized in that: The assembly process in step S6 specifically includes the following steps: S61: completing the fitting of the world coordinate system of the assembled component and the origin of the world coordinate system of the assembling component; S62: completing the fitting of the world coordinate system of the assembled component and the X-axis and Y-axis of the world coordinate system of the assembly component; S63: completing the fitting of the world coordinate system of the assembled component and the Z axis and U axis of the world coordinate system of the assembling component; S64: Correct the corresponding coordinates according to the fitting data, and complete the assembly using the six-dimensional mobile platform.

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