Rapid modeling and spraying robot based on 3D vision

Abstract

The invention belongs to the technical field of industrial automation, particularly relates to a rapid modeling and spraying robot based on 3D vision, and provides the following scheme aiming at poor flexibility during 3D collection and reduction of accuracy of 3D collection data: a tool cross frame mounted on the ground; the scanning adjusting module is arranged on the tool transverse frame, and the position where 3D collection is needed is flexibly adjusted through the scanning adjusting module, so that the 3D visual scanning device can work in a large range; and the scanning anti-shake module is fixedly connected to the scanning adjustment module, and vibration generated in the adjustment movement during 3D scanning is reduced through the scanning anti-shake module. The rapid modeling and spraying robot based on 3D vision has the advantages that the position needing 3D collection can be flexibly adjusted, the 3D vision scanning device can work in a large range, the 3D collection flexibility is improved, and therefore the accuracy of 3D collection data is improved.

Description

Technical Field

[0001] This invention relates to the field of industrial automation technology, and in particular to a 3D vision-based rapid modeling and painting robot. Background Technology

[0002] During the painting process of parts, it is necessary to perform rapid 3D vision modeling of the parts. 3D vision technology is a high-tech technology that integrates optics, mechanics, electronics, and computer technology. It is mainly used to scan the spatial shape and structure of objects to obtain the spatial coordinates of the object's surface. After obtaining the outline of the parts, the painting equipment automatically generates the painting trajectory, thereby improving the uniformity and thickness consistency of the coating and effectively improving the painting quality.

[0003] Currently, when using 3D vision technology to collect and measure painted parts, scanners are usually set up around the parts for collection. The scanner position is fixed, which makes the collection station position fixed, resulting in poor flexibility during 3D collection and reducing the accuracy of 3D collection data. Summary of the Invention

[0004] This invention discloses a rapid 3D vision modeling approach, aiming to solve the technical problems of poor flexibility and reduced accuracy of 3D acquisition data in the background technology.

[0005] The present invention proposes a rapid 3D vision-based modeling method, including:

[0006] The tooling frame is installed on the ground;

[0007] The scanning adjustment module is mounted on the tooling crossbeam. The scanning adjustment module allows for flexible adjustment of the position to be acquired in 3D, enabling the 3D vision scanning device to operate over a wide range.

[0008] The scanning anti-shake module is fixedly connected to the scanning adjustment module. It reduces the vibration generated during adjustment movement during 3D scanning.

[0009] In a preferred embodiment, the scanning adjustment module includes:

[0010] The tooling movable seat is slidably connected to the tooling cross frame. An installation port is opened on one side of the tooling movable seat, and a tooling circular frame is fixedly connected inside the installation port.

[0011] A lead screw motor is fixedly connected to one side of the tooling moving base, and a bevel gear is fixedly connected to the drive end of the lead screw motor;

[0012] The horizontal adjustment toothed plate is connected to the outside of the tooling circular frame via bearings.

[0013] In a preferred embodiment, the scan adjustment component further includes:

[0014] An adjusting motor is fixedly connected to one side of the tooling moving seat. An adjusting gear is fixedly connected to the drive end of the adjusting motor, and the adjusting gear meshes with the horizontal adjusting tooth plate.

[0015] Two limiting cylinders are provided, with one side of each limiting cylinder fixedly connected to one side of the horizontal adjusting toothed plate. Lifting cylinders are slidably connected inside both limiting cylinders, and the same lifting support plate is fixedly connected to one side of each lifting cylinder.

[0016] In a preferred embodiment, the scanning adjustment module further includes:

[0017] The limit block is movably connected inside the lifting support plate. A screw nut tube is fixedly connected to one side of the limit block, and a guide frame is fixedly connected to one side of the tooling round frame. The screw nut tube slides inside the guide frame.

[0018] The guide rail is fixedly connected to one side of the lifting support plate. An adjusting slider is slidably connected inside the guide rail. A round hole is opened on both sides of the adjusting slider. The two round holes are connected to the same adjusting cylinder through bearings. An electric drive rod is fixedly connected to one side of the guide rail. The drive end of the electric drive rod is fixedly connected to one side of the adjusting slider.

[0019] A bidirectional motor is fixedly connected to one side of the adjusting slider. The drive end of the bidirectional motor is connected to one side of the adjusting cylinder via a coupling. A second circular hole is provided on one side of the tooling frame. An adjusting screw is connected to the inside of the second circular hole via a bearing. A bevel gear is fixedly connected to one end of the adjusting screw. The first bevel gear meshes with the second bevel gear.

[0020] In a preferred embodiment, the scanning adjustment module further includes:

[0021] An arc-shaped limiting frame is fixedly connected to the outside of the adjusting cylinder. A sliding groove is provided on one side of the arc-shaped limiting frame. An arc-shaped slider is slidably connected inside the sliding groove. A return spring is fixedly connected to one side of the arc-shaped slider. One side of the return spring is fixedly connected to one side of the arc-shaped limiting frame.

[0022] The winding reel is connected to the arc-shaped limiting frame via a bearing. A circular hole three is provided on one side of the arc-shaped limiting frame. An anti-wear guide frame is fixedly connected inside the circular hole three. A winding rope is fixedly connected to one side of the arc-shaped slider. One end of the winding rope passes through the anti-wear guide frame and wraps around the outside of the winding reel.

[0023] In a preferred embodiment, the scanning adjustment module further includes:

[0024] The winding motor is fixedly connected to one side of the arc-shaped limiting frame, and the drive end of the winding motor is connected to one side of the winding reel via a coupling.

[0025] The 3D scanner itself is located on one side of the curved slider.

[0026] In a preferred embodiment, the scanning stabilization module includes:

[0027] A U-shaped support frame is fixedly connected to one side of an arc-shaped slider. Circular grooves are equally spaced on both sides of the U-shaped support frame. A buffer spring is fixedly connected inside each of the multiple circular grooves. A support cylinder is fixedly connected to one side of each of the multiple buffer springs. One side of the support cylinder is fixedly connected to one side of the 3D scanner body.

[0028] The limiting track is fixedly connected to one side of the U-shaped support frame. Inside the limiting track, there are two buffer sliders that slide together. On the opposite side of the two buffer sliders, there are two buffer springs.

[0029] In a preferred embodiment, the scanning stabilization module further includes:

[0030] An airbag is installed inside the limiting track, with one side of the airbag abutting against one side of the buffer slider;

[0031] The mounting blocks are fixedly connected to one side of the buffer slider, and each of the two mounting blocks has a support arm connected to one side via a bearing.

[0032] In a preferred embodiment, the scanning stabilization module further includes:

[0033] Support arm two is connected to one end of support arm one via bearings. Support arm one and support arm two are fixedly connected to the opposite side of each other by two compression springs. Support arm two is connected to the outside of the two support arms two via bearings by two buffer plates. One side of the buffer plate abuts against one side of the 3D scanner body.

[0034] The painting robot includes 3D vision-based rapid modeling as described above, and also includes a cantilever painting robot, wherein the cantilever painting robot is set on one side of the tooling crossbeam, and a painting robot control cabinet and a ground-mounted painting robot are respectively set above the ground.

[0035] As can be seen from the above, the 3D vision-based rapid modeling provided by the present invention has the beneficial effect of enabling flexible adjustment of the position to be acquired in 3D, allowing the 3D vision scanning device to work within a large range, improving the flexibility of 3D acquisition and thus improving the accuracy of 3D acquisition data. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of the 3D vision-based rapid modeling proposed in this invention;

[0037] Figure 2 This is a schematic diagram of the scanning adjustment module structure based on rapid 3D vision modeling proposed in this invention;

[0038] Figure 3 This is a cross-sectional view of the arc-shaped limiting frame based on rapid 3D vision modeling proposed in this invention;

[0039] Figure 4 This is a schematic diagram of the scanning anti-shake module structure based on 3D vision rapid modeling proposed in this invention;

[0040] Figure 5 This is a partial structural diagram of the scanning anti-shake module based on 3D vision rapid modeling proposed in this invention;

[0041] Figure 6 This is a schematic diagram of the tooling crossbeam structure based on rapid 3D vision modeling proposed in this invention;

[0042] Figure 7 This is a schematic diagram of the overall structure of the painting robot proposed in this invention.

[0043] In the diagram: 1. Spray painting robot control cabinet; 2. Cantilever spray painting robot; 3. Ground-mounted spray painting robot; 4. Tooling crossbeam; 5. Scanning and adjustment module; 501. Tooling moving seat; 502. Adjustment motor; 503. Adjustment gear; 504. Tooling circular frame; 505. Adjustment screw; 506. Bevel gear one; 507. Screw motor; 508. Bevel gear two; 509. Horizontal adjustment gear plate; 510. Limiting cylinder; 511. Lifting cylinder; 512. Screw nut tube; 513. Limiting block; 514. Guide rail; 515. Electric drive rod; 516. Adjustment slider; 517. Adjustment cylinder; 518. 519. Bidirectional motor; 520. Arc-shaped limit frame; 521. Rewind motor; 522. Arc-shaped slider; 523. Return spring; 524. Rewind rope; 525. Anti-wear guide frame; 526. Rewind reel; 527. 3D scanner body; 528. Lifting support plate; 529. Guide frame; 600. Scanning anti-shake module; 601. U-shaped support frame; 602. Buffer spring one; 603. Support cylinder; 604. Buffer slider; 605. Limiting track; 606. Airbag; 607. Buffer spring two; 608. Mounting block; 609. Support arm one; 610. Support arm two; 611. Compression spring; 612. Buffer stop plate. Detailed Implementation

[0044] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0045] The rapid modeling based on 3D vision disclosed in this invention is mainly applied to scenarios where the flexibility of 3D acquisition is poor and the accuracy of 3D acquisition data is reduced.

[0046] Reference Figures 1-6 Based on rapid 3D vision modeling, including:

[0047] Tooling frame 4, installed on the ground;

[0048] The scanning adjustment module 5 is set on the tooling crossbeam 4. The position to be acquired by 3D acquisition can be flexibly adjusted through the scanning adjustment module 5, so that the 3D vision scanning device can work in a large range.

[0049] The scanning anti-shake module 6 is fixedly connected to the scanning adjustment module 5. The scanning anti-shake module 6 reduces the vibration generated during adjustment movement during 3D scanning.

[0050] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 6 In a preferred embodiment, the scanning adjustment module 5 includes:

[0051] The tooling movable seat 501 is slidably connected to the tooling cross frame 4. An installation port is provided on one side of the tooling movable seat 501, and a tooling circular frame 504 is fixedly connected inside the installation port.

[0052] A lead screw motor 507 is fixedly connected to one side of the tooling moving seat 501, and a bevel gear 508 is fixedly connected to the drive end of the lead screw motor 507.

[0053] The horizontal adjustment toothed plate 509 is connected to the outside of the tooling frame 504 via a bearing.

[0054] In this invention, the scanning adjustment component further includes:

[0055] An adjusting motor 502 is fixedly connected to one side of the tooling moving seat 501. An adjusting gear 503 is fixedly connected to the drive end of the adjusting motor 502. The adjusting gear 503 meshes with the horizontal adjusting toothed plate 509.

[0056] Two limiting cylinders 510 are fixedly connected to one side of the horizontal adjusting toothed plate 509 on one side. Lifting cylinders 511 are slidably connected inside the two limiting cylinders 510. The same lifting support plate 527 is fixedly connected to one side of the two lifting cylinders 511.

[0057] In this invention, the scanning adjustment module 5 further includes:

[0058] The limiting block 513 is movably connected inside the lifting support plate 527. A screw nut tube 512 is fixedly connected to one side of the limiting block 513, and a guide frame 528 is fixedly connected to one side of the tooling round frame 504. The screw nut tube 512 slides inside the guide frame 528.

[0059] The guide rail 514 is fixedly connected to one side of the lifting support plate 527. An adjusting slider 516 is slidably connected inside the guide rail 514. A round hole is opened on both sides of the adjusting slider 516. The two round holes are connected to the same adjusting cylinder 517 through bearings. An electric drive rod 515 is fixedly connected to one side of the guide rail 514. The driving end of the electric drive rod 515 is fixedly connected to one side of the adjusting slider 516.

[0060] A bidirectional motor 518 is fixedly connected to one side of the adjusting slider 516. The drive end of the bidirectional motor 518 is connected to one side of the adjusting cylinder 517 via a coupling. A second circular hole is provided on one side of the tooling frame 504. An adjusting screw 505 is connected to the inside of the second circular hole via a bearing. A bevel gear 506 is fixedly connected to one end of the adjusting screw 505. The bevel gear 506 meshes with the second bevel gear 508.

[0061] In this invention, the scanning adjustment module 5 further includes:

[0062] An arc-shaped limiting frame 519 is fixedly connected to the outside of the adjusting cylinder 517. A sliding groove is provided on one side of the arc-shaped limiting frame 519. An arc-shaped slider 521 is slidably connected inside the sliding groove. A return spring 522 is fixedly connected to one side of the arc-shaped slider 521. One side of the return spring 522 is fixedly connected to one side of the arc-shaped limiting frame 519.

[0063] The winding reel 525 is connected to the arc-shaped limiting frame 519 via a bearing. A circular hole 3 is provided on one side of the arc-shaped limiting frame 519. An anti-wear guide frame 524 is fixedly connected inside the circular hole 3. A winding rope 523 is fixedly connected to one side of the arc-shaped slider 521. One end of the winding rope 523 passes through the anti-wear guide frame 524 and wraps around the outside of the winding reel 525.

[0064] In this invention, the scanning adjustment module 5 further includes:

[0065] The winding motor 520 is fixedly connected to one side of the arc-shaped limiting frame 519, and the drive end of the winding motor 520 is connected to one side of the winding reel 525 through a coupling.

[0066] The 3D scanner body 526 is located on one side of the curved slider 521.

[0067] In a specific application scenario, when 3D scanning a component, the lead screw motor 507 is activated. The lead screw motor 507 drives the bevel gear 508, causing the bevel gear 506 to rotate. This, in turn, causes the adjusting lead screw 505 to rotate. The adjusting lead screw 505 then drives the lead screw nut tube 512 to rise and fall under the limit of the guide frame 528. This causes the lead screw nut tube 512 to move the 3D scanner body 526 below the lifting support plate 527. The adjusting motor 502 is then activated, driving the adjusting gear 503 to rotate the horizontal adjusting gear plate 509. The horizontal adjusting gear plate 509, through the limiting cylinder 510 and the lifting cylinder 511, moves the 3D scanner body 526 below the lifting support plate 527. The 3D scanner body 526 rotates, and the bidirectional motor 518 drives the adjusting cylinder 517 to adjust the angle of the 3D scanner body 526 on the arc-shaped limiting frame 519. At the same time, by starting the winding motor 520, the winding reel 525 winds up and unwinds the winding rope 523, so that the elasticity of the return spring 522 causes the arc-shaped slider 521 to move on the arc-shaped limiting frame 519, thereby adjusting the angle of the 3D scanner body 526. When 3D scanning parts, the scanning adjustment module 5 can flexibly adjust the position to be 3D acquired, so that the 3D vision scanning device can work within a large range, improving the flexibility of 3D acquisition and thus improving the accuracy of 3D acquired data.

[0068] Reference Figure 1 , Figure 4 and Figure 5 In a preferred embodiment, the scan stabilization module 6 includes:

[0069] The U-shaped support frame 601 is fixedly connected to one side of the arc-shaped slider 521. Circular grooves are equally spaced on both sides of the U-shaped support frame 601. Buffer springs 602 are fixedly connected inside the multiple circular grooves. Support cylinders 603 are fixedly connected to one side of the multiple buffer springs. One side of the support cylinder 603 is fixedly connected to one side of the 3D scanner body 526.

[0070] The limiting track 605 is fixedly connected to one side of the U-shaped support frame 601. Two buffer sliders 604 are slidably connected inside the limiting track 605. Two buffer springs 607 are fixedly connected to the opposite side of the two buffer sliders 604.

[0071] In this invention, the scanning stabilization module 6 further includes:

[0072] Airbag 606 is disposed inside the limiting track 605, and one side of airbag 606 abuts against one side of buffer slider 604;

[0073] Mounting block 608 is fixedly connected to one side of buffer slider 604, and support arm 609 is connected to one side of both mounting blocks 608 via bearings.

[0074] In this invention, the scanning stabilization module 6 further includes:

[0075] Support arm 2 610 is connected to one end of support arm 1 609 via bearings. Support arm 1 609 and support arm 2 610 are fixedly connected to two compression springs 611 on opposite sides. Support arms 2 610 are connected to two buffer plates 612 via bearings on the outside. One side of buffer plate 612 abuts against one side of 3D scanner body 526.

[0076] In specific application scenarios, when adjusting the 3D scanner body 526, the 3D scanner body 526 uses a buffer spring 602 to reduce the vibration generated during movement. When the buffer spring 602 is compressed, the buffer plate 612 is stressed, which in turn compresses the compression spring 611 and the second buffer spring 607, causing the buffer slider 604 to move towards the airbag 606. This reduces the rebound force of the buffer spring 602, minimizing the vibration generated by the 3D scanner body 526 during adjustment and movement, and improving the accuracy of 3D data acquisition.

[0077] Reference Figure 7 The painting robot includes the 3D vision-based rapid modeling as described above, and also includes a cantilever painting robot 2. The cantilever painting robot 2 is set on one side of the tooling frame 4, and a painting robot control cabinet 1 and a ground-mounted painting robot 3 are respectively set above the ground.

[0078] Working principle: When using,

[0079] When 3D scanning the parts, the lead screw motor 507 is activated, which drives the bevel gear 508 to rotate the bevel gear 506. The bevel gear 506 then rotates the adjusting lead screw 505. The adjusting lead screw 505 then moves the lead screw nut tube 512 up and down under the limit of the guide frame 528, causing the 3D scanner body 526 below the lifting support plate 527 to move up and down. The adjusting motor 502 is activated, which drives the adjusting gear 503 to rotate the horizontal adjusting toothed plate 509. The horizontal adjusting toothed plate 509, through the limiting cylinder 510 and the lifting cylinder 511, rotates the 3D scanner body 526 below the lifting support plate 527. The bidirectional motor 518 drives the adjusting cylinder 517 to adjust the angle of the 3D scanner body 526 on the arc-shaped limiting frame 519. Simultaneously, the winding motor 518 is activated. 20, causing the take-up reel 525 to retract and extend the take-up rope 523, thereby causing the elasticity of the return spring 522 to move the arc-shaped slider 521 on the arc-shaped limit frame 519, thereby adjusting the angle of the 3D scanner body 526. When adjusting the 3D scanner body 526, the 3D scanner body 526 reduces the vibration generated during movement through the buffer spring 602. When the buffer spring 602 is compressed, the buffer plate 612 is stressed, thereby compressing the compression spring 611 and the second buffer spring 607 respectively, causing the buffer slider 604 to move towards the airbag 606, thereby reducing the rebound force of the buffer spring 602 and minimizing the vibration generated by the 3D scanner body 526 during adjustment. After the part contour data is collected, the cantilevered spray painting robot 2 and the ground-mounted spray painting robot 3 are controlled by the spray painting robot control cabinet 1 to automatically spray the parts.

[0080] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A rapid modeling method based on 3D vision, characterized in that, include: The tooling frame is installed on the ground; The scanning adjustment module is mounted on the tooling crossbeam. The scanning adjustment module allows for flexible adjustment of the position to be acquired in 3D, enabling the 3D vision scanning device to operate over a wide range. The scanning anti-shake module is fixedly connected to the scanning adjustment module. It reduces the vibration generated during adjustment movement during 3D scanning.

2. The rapid modeling based on 3D vision according to claim 1, characterized in that, The scanning adjustment module includes: The tooling movable seat is slidably connected to the tooling cross frame. An installation port is opened on one side of the tooling movable seat, and a tooling circular frame is fixedly connected inside the installation port. A lead screw motor is fixedly connected to one side of the tooling moving base, and a bevel gear is fixedly connected to the drive end of the lead screw motor; The horizontal adjustment toothed plate is connected to the outside of the tooling circular frame via bearings.

3. The rapid modeling based on 3D vision according to claim 2, characterized in that, The scan adjustment component further includes: An adjusting motor is fixedly connected to one side of the tooling moving seat. An adjusting gear is fixedly connected to the drive end of the adjusting motor, and the adjusting gear meshes with the horizontal adjusting tooth plate. Two limiting cylinders are provided, with one side of each limiting cylinder fixedly connected to one side of the horizontal adjusting toothed plate. Lifting cylinders are slidably connected inside both limiting cylinders, and the same lifting support plate is fixedly connected to one side of each lifting cylinder.

4. The rapid modeling based on 3D vision according to claim 3, characterized in that, The scanning adjustment module also includes: The limit block is movably connected inside the lifting support plate. A screw nut tube is fixedly connected to one side of the limit block, and a guide frame is fixedly connected to one side of the tooling round frame. The screw nut tube slides inside the guide frame. The guide rail is fixedly connected to one side of the lifting support plate. An adjusting slider is slidably connected inside the guide rail. A round hole is opened on both sides of the adjusting slider. The two round holes are connected to the same adjusting cylinder through bearings. An electric drive rod is fixedly connected to one side of the guide rail. The drive end of the electric drive rod is fixedly connected to one side of the adjusting slider. A bidirectional motor is fixedly connected to one side of the adjusting slider. The drive end of the bidirectional motor is connected to one side of the adjusting cylinder via a coupling. A second circular hole is provided on one side of the tooling frame. An adjusting screw is connected to the inside of the second circular hole via a bearing. A bevel gear is fixedly connected to one end of the adjusting screw. The first bevel gear meshes with the second bevel gear.

5. The rapid modeling based on 3D vision according to claim 4, characterized in that, The scanning adjustment module also includes: An arc-shaped limiting frame is fixedly connected to the outside of the adjusting cylinder. A sliding groove is provided on one side of the arc-shaped limiting frame. An arc-shaped slider is slidably connected inside the sliding groove. A return spring is fixedly connected to one side of the arc-shaped slider. One side of the return spring is fixedly connected to one side of the arc-shaped limiting frame. The winding reel is connected to the arc-shaped limiting frame via a bearing. A circular hole three is provided on one side of the arc-shaped limiting frame. An anti-wear guide frame is fixedly connected inside the circular hole three. A winding rope is fixedly connected to one side of the arc-shaped slider. One end of the winding rope passes through the anti-wear guide frame and wraps around the outside of the winding reel.

6. The rapid modeling based on 3D vision according to claim 5, characterized in that, The scanning adjustment module also includes: The winding motor is fixedly connected to one side of the arc-shaped limiting frame, and the drive end of the winding motor is connected to one side of the winding reel via a coupling. The 3D scanner itself is located on one side of the curved slider.

7. The rapid modeling based on 3D vision according to claim 6, characterized in that, The scanning stabilization module includes: A U-shaped support frame is fixedly connected to one side of an arc-shaped slider. Circular grooves are equally spaced on both sides of the U-shaped support frame. A buffer spring is fixedly connected inside each of the multiple circular grooves. A support cylinder is fixedly connected to one side of each of the multiple buffer springs. One side of the support cylinder is fixedly connected to one side of the 3D scanner body. The limiting track is fixedly connected to one side of the U-shaped support frame. Inside the limiting track, there are two buffer sliders that slide together. On the opposite side of the two buffer sliders, there are two buffer springs.

8. The rapid modeling based on 3D vision according to claim 7, characterized in that, The scanning stabilization module also includes: An airbag is installed inside the limiting track, with one side of the airbag abutting against one side of the buffer slider; The mounting blocks are fixedly connected to one side of the buffer slider, and each of the two mounting blocks has a support arm connected to one side via a bearing.

9. The rapid modeling based on 3D vision according to claim 8, characterized in that, The scanning stabilization module also includes: Support arm two is connected to one end of support arm one via bearings. Support arm one and support arm two are fixedly connected to the opposite side of each other by two compression springs. Support arm two is connected to the outside of the two support arms two via bearings by two buffer plates. One side of the buffer plate abuts against one side of the 3D scanner body.

10. A painting robot, comprising the 3D vision-based rapid modeling as described in any one of claims 1-9, characterized in that, It also includes a cantilevered painting robot, which is set on one side of the tooling frame, with a painting robot control cabinet and a ground-mounted painting robot respectively installed above the ground.

Images