Cable robot for coating procedures

Abstract

The present invention refers to an automated painting system on oil ships, being executed by a mobile platform and an oscillating arm. The assembly only works due to the control of cables, winders and wheels. This approach is aimed at painting large vertical walls. The painting deck suspension uses four cables, each connected to a pivot on the mobile platform, and two fixed pivots plus four winders. The winders contain a servo motor in a synchronous serial network. The cables are made of reduced-weight polyethylene. Each cable is connected exclusively to one winder. Suspension is achieved with the aid of two adapted cranes and initialization through the addition of a giraffe-type crane.

Claims

1. A cable robot used in a coating process, the cable robot comprising: two fixed pivots; four movable pivots; four cables; four winders; a process effectuator or mobile platform for carrying a coating or paint applicator arm and oscillating mechanism assembly, two cranes; and an electronic control unit, wherein the four cables comprise a reduced-weight polyethylene material, with the four cables connected two-by-two to each of the fixed pivots that are at deck height on a ship, and the four cables suspend the mobile platform connected to the moveable pivots.

2. The cable robot of claim 1, wherein the mobile platform is moved by the four winders that act on the four cables through the electronic control unit.

3. The cable robot of claim 1, wherein each of the winders includes a load cell for measuring force applied to at least one of the four cables and a compensation of a free length between each of the winders and the mobile platform, and also each of the winders includes a servo motor in a synchronous serial network.

4. The cable robot of claim 1, wherein the mobile platform is initially positioned by an additional crane and the two cranes.

5. A cable robot used in a coating process, the cable robot comprising: two fixed pivots; four movable pivots; four cables; four winders; a process effectuator or mobile platform for carrying a coating or paint applicator arm and oscillating mechanism assembly, two cranes; and an electronic control unit, wherein the four winders are installed on the two cranes, and the two cranes include two supports, wherein one of the supports is aligned with a crane boom and the other one of the supports is tilted to a side of the four cables.

6. The cable robot of claim 5, wherein the mobile platform is moved by the four winders that act on the four cables through the electronic control unit.

7. The cable robot of claim 5, wherein each of the winders includes a load cell for measuring force applied to at least one of the four cables and a compensation of a free length between each of the winders and the mobile platform, and also each of the winders includes a servo motor in a synchronous serial network.

8. The cable robot of claim 5, wherein the mobile platform is initially positioned by an additional crane and the two cranes.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The detailed description presented below references the attached figures and their respective reference numbers.

(2) FIG. 1 shows the layout of the painting platform suspended by four cables, each cable on a winder, located on a vertical wall.

(3) FIG. 2 shows the process effectuator, detailing the anchor points.

(4) FIGS. 3A to 3F show the winder detail.

(5) FIG. 4 shows the layout of a crane, from a side view, which will be the anchoring point of the painting platform.

(6) FIG. 5 shows a crane, a giraffe crane, and the painting platform.

(7) FIG. 6 shows the painting platform suspended by the two cranes, and the effective painting area.

DETAILED DESCRIPTION OF THE INVENTION

(8) The purpose of the present invention is to use a type of cabling configuration to suspend a mobile platform, developed to couple an oscillating mechanism that performs the painting process, and also to move rapidly and accurately to ensure the quality of painting on ship hulls, but not being restricted to this application.

(9) For a better understanding of the invention, we will illustrate it by means of the following description, which is a preferred embodiment of the invention. As will be apparent to anyone skilled in the art, however, the invention is not limited to that particular embodiment.

(10) The present invention, related to the arrangement of cables for suspension of the mobile platform (3), is new because it is positioned by four cables, with its suspension system placed on free “Mecanum” wheels (21) that behave like spheres. In this case it has two fixed pivots at deck height, which will be the base of the structure that suspends the suspended mobile platform, and four mobile pivots at the ends of the mobile platform. The cables are controlled by four different winders (19) that work independently, all of which are evaluated in real-time to determine the tension on each cable, thus enabling real-time correction of the trajectory, taking into account factors such as elasticity of the cable, the friction factor of the winders, and the variation of the load on the system.

(11) The mobile platform (3) intended to receive the oscillating mechanism must be installed by hoisting, using two cranes (20), as the assembly weighs 180 kg. In addition, the mobile platform (3) on the hull must be installed using a giraffe-type crane (14).

(12) The mobile suspended platform (3) is positioned by the cables, with its suspension system placed on free Mecanum wheels that behave like spheres.

(13) The principle, shown in FIG. 1, is based on the positioning of a mobile platform (3) suspended by four cables. In this case it will have two fixed pivots (1) at deck height, which will be the base of the structure that suspends the suspended mobile platform (3), and four mobile pivots (2) at the ends of the suspended mobile platform (3). This suspended mobile platform (3) will carry a coating or paint applicator arm, with a sweeping dynamic suitable for the painting process.

(14) This suspended mobile platform and oscillating mechanism assembly (22) will be the project's process effectuator (8).

(15) The connection of these six points, two on the hull represented by fixed pivots (1) and four on the mobile platform (3) represented by mobile pivots (2), in this case is suspended by four cables that will create three triangles with two concurrent sides. Thus the first two cables (4) and (5) come out of winders 1 and 2 concurrently at the same point projected on the 2D plane of the hull, as the two mobile pivots (2) on the suspended mobile platform (3).

(16) The 3rd “third” (6) and 4th “fourth” cable (7) leave the concurrent point of winders 3 and 4. Cable 3 (6) reaches a concurrent point with cable 2 and the 4th “fourth” cable reaches the 3rd “third” suspension point of the suspended mobile platform (3).

(17) The winding mechanism, FIGS. 3A to 3F, is the assembly that positions the mobile platform on the wall. The concept is a precise winder with only one layer of cable on the drum, and the axial movement of the drum pulled by a static trapezoidal spindle. FIGS. 3A to 3F show the dimension of a winder with technical details.

(18) In addition to the single-layer winding mechanism, the winding assembly also has a load cell for measuring the force applied to the cable and compensating for the free length between the winder and the platform. This feature is necessary in this redundant kinematic solution of four cables controlling three degrees of freedom (X, Y and A). With the load measurement we will offset the deformation of the cables, as the forces vary greatly depending on the position of the platform in the work area. In the general sizing of this system, the calculated load on the cables varies from 4 N to 3,545 kN. The maximum load represents 16% of the guaranteed rupture load of the cables.

(19) FIG. 4 shows a crane in side view, serving as a pivot point for 2 cables. The lifting mechanism for the cable robot is an assembly comprising a crane, with two additional supports (10), one aligned with the crane boom (11), and the other tilted to the side of the robot cables, as shown in FIG. 5. In this case, work is done in compression so that the robot can be installed even close to side obstacles with the housing and the bases of the cranes on the platform. The crane has a base framework with wheels for transport across the deck to the installation point, threaded feet for support directly to the floor, lifting the wheels from contact with the ground. The crane boom (11) uses the cable winders (winches) as a counterweight, so it applies its weight to the pivot of the crane's base framework. The base framework has an integrated control panel that acts as ballast on the opposite side of the crane's pivot, so as to bring the center of gravity over the area between the wheels.

(20) With the crane assembly pre-assembled according to the arrangement indicated in FIG. 4, the assembly must be positioned, still using the wheels until it is close to the guardrail (9) on the side. Care must be taken to smoothly stop the assembly as the center of gravity of this configuration is high and forward, almost over the wheels under the boom. This causes the assembly to topple over easily. If this assembly is released and bumps against the false edge (12), it will likely topple over the guardrail (9) and fall towards the sea (13).

(21) To launch the assembly (22) of the mobile platform and the oscillating mechanism from the deck to the side of the platform, a giraffe-type manual crane (14) must be used, as the assembly has a mass of 180 kg, being hoisted by the painting platform release cable (15).

(22) Due to the risk of working with this type of force close to the guardrail, and due to the fact that the entire length of the side is not covered by cranes on the platform, especially in the area chosen for testing, where the crane does not reach, the launch procedure must be done using the robot's own winders. In order to have the capacity to hoist the winders for the launch, the launch must be done close to one of the cranes (20), normally 5.5 m and far away from each other. FIG. 5 shows this distance close to one of the cranes.

(23) FIG. 6 shows the crane-winder assembly (17) on both the left and right sides in operation. Also shown is the threshold of the vertical paint range and the final horizontal range (18). As an example, the effective painting area is shown, in this case 17×51 m.sup.2.

(24) Please be advised that the use of the cable system, cranes and winders is not restricted to the embodiment shown here, as they can be used in any application.