WO1986001171A1

WO1986001171A1 - Apparatus for the observation and/or treatment of an immersed surface

Info

Publication number: WO1986001171A1
Application number: PCT/FR1985/000220
Authority: WO
Inventors: Patrick Blevanus; Robert Bodson
Original assignee: International Robotic Engineering Inc.
Priority date: 1984-08-14
Filing date: 1985-08-13
Publication date: 1986-02-27
Also published as: EP0191810A1; FR2569140B1; FR2569140A1

Abstract

Automated apparatus for the control and/or brushing of hulls of ships or similar works. The aim is to constantly keep the tools (3, 4) at an optimum distance from the surface (7) to be treated or monitored. To this effect, actuation means (16, 14) capable of displacing the tool with respect to the surface are controlled by data processing means receiving data from sensors which are sensitive to the distance separating the tool from the surface. Preferably, a data processing control unit (19) is arranged at a fixed station and is connected to the tools and to the actuation means by a flexible umbilical tether (20). Conveniently, the actuation means act on wheels (5, 6) which run on the surface.

Description

Apparatus for the observation and / or treatment of a submerged surface ^f

The present invention relates to an apparatus for the observation and treatment of a submerged surface, such as a ship's hull.

The maintenance of ships' hulls includes various operations including brushing, intended to remove the old paint and to expose the sheet metal, sometimes accompanied by a polishing, a visual inspection to detect cracks and possible defects, then the deposit of new layers of paint, often combined with a passivation treatment. It also happens that an ultrasound treatment intended to destroy the microbial veil is practiced.

All these operations are carried out either in dry dock or when the ship is afloat. Dry dock work requires one _. immobilization when, on the other hand, the number of dry docks available is often insufficient. Afloat work is delicate and normally requires the presence of divers. We have proposed, EP-A-0 084 012, a robot capable of processing a shell and of moving thereon by its own means thanks to two movable crews relative to each other and each provided with means attachment on the surface, these means being movable in the direction perpendicular to this surface. In this device, one of the crews carries the treatment tool (s) at the end of a pivoting arm. Such an apparatus is powerful and effective, but its speed of movement is limited by the fact that it is propagated by successive movements of one crew relative to the other.

The object of the present invention is to provide an apparatus which is capable of performing the same functions but with higher travel speeds. Apparatuses are already known which comprise: a rigid chassis, wheels carried by the chassis and intended to come to bear on the surface, hydraulic means, carried by the chassis and capable of exerting on it a force directed towards the surface, at least one observation and / or processing tool carried by the chassis.

Such devices allow relatively rapid movement from one point to another, thanks to the wheels with which they are equipped, but they are not automated and are designed to be driven by a diver. In addition, especially when it comes to brushing, maintaining the brushes in a suitable position relative to the surface, poses a poorly resolved problem. Indeed, current brushes are circular brushes which rotate around an axis perpendicular to the surface. The rotation of these brushes projects the water outward under the effect of centrifugal force and generates, in return, a suction effect which tends to press the brush on the surface, which reduces the efforts required of the plunger. Unfortunately, the irregularities of the surface mean that the wheels and the brush are not always in the same plane, and the distance from the brush to the surface is not constant, resulting in irregular brushing. The connection of the brushes to the device may include springs to alleviate these drawbacks, but this does not make it possible to eliminate them. . As a result, the treatment time consumes more time and energy than is necessary, if a complete brushing is desired. The apparatus of the present invention has to solve this problem.

The invention provides for this an apparatus of the type indicated above, that is to say comprising: a rigid chassis, - wheels carried by the chassis and intended to come to bear on the surface, hydraulic means, carried by the chassis and capable of exerting on it a force directed towards the surface, - at least one observation and / or treatment tool carried by the chassis, and which has the following particularities:

- at least one sensor sensitive to the distance of the tool from the surface, - actuation means capable of moving said tool perpendicular to the surface, computer means, capable of receiving signals from said sensor and emitting in response to control signals for said actuating means for maintaining the tool at the desired distance from the surface.

It follows from this structure that the tool can deviate from the optimal position defined in advance only during the very short time which corresponds to the response time of the apparatus.

Preferably, the computer means are separated from the chassis and connected to it by a fiber optic link means and means for transforming the signals emitted by the sensor and the control signals into optical signals and vice versa, and advantageously , IT resources are common to several chassis, and operate on a timeshare basis. IT resources, which are an expensive and relatively fragile part of the device, can thus be protected from the vagaries of work in submerged condition and 3.e cost price can be reduced.

The actuating means capable of moving the tool relative to the surface preferably comprises a stepping motor for simplification of the computer means and for greater stability of the tool when passing over small irregularities of the surface.

The actuation means capable of moving the tool relative to the surface can be interposed between the tool and the chassis. It is however advantageous to provide that at least some of these are arranged to change the position of at least one wheel relative to the chassis. It is thus easier to couple them with means for immobilizing the device for work on a particular location. It can thus be provided that this wheel is a steerable wheel and is carried by a movable arm perpendicular to the surface and further provided with actuating means for rotating the wheel around an axis perpendicular to the surface and that the the apparatus further comprises a tool support arm, mounted for rotation on the chassis, this support arm being provided with a clutch which, when it is engaged, makes the support arm secured to said movable arm, enables said arm relative to the chassis using said wheel actuating means, and which, when disengaged, maintains said support arm in a fixed position relative to the chassis. It can be seen that these provisions make it possible to limit the number of actuators.

According to an advantageous embodiment of the invention, the hydraulic means consist of a turbine formed by a full internal disc, an external disc pierced at its center, and blades located between these two discs, scraping, brushing or polishing means of the surface are carried by the external face of the internal disc. This arrangement makes it possible to obtain a force directed towards the surface, but which depends little on the nature of the tool and its distance from the surface. In particular, this shape remains even when the tool is far from any surface and can be used to propel the device, which is not the case in systems where these means are constituted by the brush itself: in these systems, the force drops to a very low value as soon as the brush moves away from contact with the surface.

- According to an interesting embodiment of the invention, it is provided that the sensors sensitive to the position of the tool are mounted on the. chassis and are in sufficient number to allow topological recognition of the surface, and in the case of a ship's hull, to identify regular flatness defects due to the presence of flanged irons and that said computer means are capable of ensuring the control and command of the movements of the device from the data of this topological recognition. This embodiment is based on the fact that the first of the flange irons welded on the internal face of the hull, at a spacing which is usually 800 mm, causes, on the external face, the existence of differences in level which are usually 2 to 3 mm and can reach 1 cm. These differences in level, which are visible in grazing light, are of a magnitude compatible with the sensitivity of the sensors.

Other modes of position recognition can be provided, in association with the one just described, or in place of the latter. In particular, provision can be made for the device to be fitted with sensors capable of detecting the welds of a shell. vessel by eddy currents and that said computer means are capable of ensuring the control and command of the movements of the apparatus using the data supplied by said sensors. Among the advantages provided by the automation of the device, it is worth mentioning the possibility of providing an ultrasonic transmitter capable of destroying a microbial veil which has developed on the surface. This microbial veil, which is initially responsible for the degradation of the paint, is generally not treated by ultrasound, because the use of these is painful and / or dangerous for divers who operate nearby. The fact of providing the device of the invention allows early treatment of the shell, and avoids higher costs.

The present invention will now be explained in more detail with the aid of practical examples, given without limitation and illustrated in the drawings, among which: - Fig. 1 is an elevational view of the device;

- Fig. la is a partial view of a variant of FIG. 1;

- Fig. 2 is a side view of the same device;

Fig. 3 is an axial half-section of a brush booster;

Fig. 4 is a half view in elevation of the same brush booster; - Fig. 5 and 6 are two variants of a section along the line A-A of FIG. 3;

Fig. 7 is a section through the means for orienting and holding the wheels;

- Fig. 8 is a block diagram of the electronic part. The apparatus shown in lines 1 and 2 corresponds to the chassis 1, the general shape of which is roughly that of a triangular plate with a front point arranged on the right in FIG. 1 and an enlarged rear side. The chassis is bordered by an anti-shock belt 2. On one of its faces, called the "internal face", the chassis carries three "propellant-brush" assemblies which will be described in more detail below, and one of which, 3 is placed near the front point of the chassis, and the other two 4 are arranged towards the rear, the three propellant-brush assemblies are arranged so as to form a substantially equilateral triangle.

An assembly 5, formed of two twin wheels is placed just behind the propellant-brush assembly 3, and two carrying wheels 6 are each placed just behind one of the propellant-brush assemblies 4.

The internal face of the chassis also carries distance sensors intended to determine the distance between the chassis 1 and a support surface 7, which is shown vertically in FIG. 2. Two sensors 8, 9 are placed respectively in front and rear of the propellant-brush assembly 3 and at a short distance from it, the others, 10, 11 are also placed a short distance from each of the other propellant assemblies. brushes and in a diametrically opposite position with respect to them.

On its opposite face or external face, the chassis 1 carries the motors 12 for driving the propellant-brush assemblies. It also carries, in a casing 12, the means for controlling the wheels 5 in propulsion, orientation and variation in height. By "height" is meant here the position, along a perpendicular to the overall plane of the chassis. The casing 13 carries, on its external face, an arm 14, pivotally mounted on an axis perpendicular to the overall plane of the chassis, and which carries an observation member 15.

The external face of the chassis also carries the means 16 for varying the height of the carrying wheels 6. It also carries two boxes 17, 18 which contain, one the switching and hydraulic control members, the other the electronic switching and control. These organs are ^" connected to the central control unit 19, located in a fixed location and independent of the chassis by an" umbilical "20 which groups, in the same sheath, the supply and return conduits of the hydraulic fluid and the optical cables for the transmission of information and control signals.

Figs. 3 to 6 illustrate the structure of the "propellant-brush" assemblies 3 and 4. The chassis 1 has a hole in which a support 21 is placed, connected to the support by an anti-vibration attachment 22. This support supports, on its external face, the drive motor 12 whose shaft passes through the support and carries a polyamide flange 23, on the periphery of which is fixed a first annular plate 24 of epoxy resin reinforced with glass fibers. A second plate 25, similar to the first, is connected to the internal face of the first plate by a series of fins 26, approximately radial, visible, in section in FIGS. 5 and 6. On its face opposite to the plate 24, that is to say on the face facing the surface to be treated or to be inspected 7, are fixed removably, a series of scraping, brushing or polishing elements 27. In the version shown in FIG. 5, one of the elements comprises a part 28, made of polyurethane with a U section, and a second part 29 of the same material, with a rectangular section, the width of which is less than the spacing of the branches of the part 28. The parts 28 and 29 are crossed by a threaded rod 30, which also passes through the two plates 24, 25 and a fin 26. This threaded rod is screwed into a nut 31 embedded in the outer plate 24 and at its other end it has a head 32 for retaining the part 29.

The fin 26 is a U-shaped section, and its position prevents the tightening of the rod 30 from causing deformation of the plates 24, 25.

Between the pieces 28 and 29 are placed a series of wires 33, of length such that they protrude, outside the pieces 28, 29, constituting the brushing members. The tightening of the rod 30 immobilizes these wires by giving them a U shape such that their ends are directed towards the surface to be treated 7. It will be appreciated that it is easy to dismantle the assembly in order to replace the wires 33 with others wires of a different stiffness, and thus pass from an energetic brushing to a soft polishing.

The variant illustrated in FIG. 6 is different from that of FIG. 5 by the shape of the part 28. The latter in fact has a wing 34 which is extended by a sharp edge 35, and thus constitutes a scraping tool.

In Fig. 6, the part 29 has been mounted tightly directly on the part 26, it is however possible to place, between the two parts, bristles 33, coming to complete the scraping action of the edge 35 by a brushing action. The role of the scraping tool, in fact, is not to remove the paint itself, but to unhook deposits or marine organisms that may have attached to the hull.

In another variant, not shown, the part 28 is a flexible material pad and it constitutes a polishing member.

Fig. 4 shows the arrangement of the brushing, scraping or polishing elements 27, which is also that of the fins 12. These elements are alternately radial and arranged. To make an angle of approximately 15 ° with a radius. This arrangement makes it possible to reduce the vibrations compared to a brush where all the elements are arranged in the same way with respect to the radius. Fig. 7 shows the detail of the actuation structure of the twin driving-driving wheels 5. A tubular support 40 movable perpendicular to the surface to be treated or observed 7 is crossed by the shaft 41 carrying the wheels 5. Inside the report 40 is placed a displacement motor 42, which rotates the shaft 4 by a conventional type transmission 43, with gear and worm.

The support 40 can move along its axis thanks to an ^' elevation motor 44 supported by a support piece 45 and which acts on the support 40 by a rack and pinion transmission 46. This support piece 45 can itself even be driven in rotation with the support 40 by means of an orientation motor 47 which acts by means of a transmission 48 with pinion and angle gear. The orientation motor 47 is supported by the chassis 1 as well as the bearing 49 which supports the support piece 45.

At its part opposite the wheels 5, the support 40 carries a clutch plate 50 which faces a similar plate 51 carried by the arm 14. -

When the support 40 is in the "fully raised" position, that is to say that, at the end of its travel in the direction opposite to the surface 7, the clutch plates 50, 51 are in contact, and the orientation motor 47 rotates the arm 14. When the support 40 deviates from this position, the arm 14 remains in the same position relative to the chassis 1 by means of a friction device.

At its lower part, the support 40 has a collar 52, on which a helical spring 53 is supported, surrounding the support. This spring, by its opposite end exerts on a tubular part 54 with a closed bottom, a force which tends to separate it from the surface 7. This part carries two permanent magnets 55 by means of a flexible blade 56. Between the tubular piece 54 and the support 40 is interposed a deformable bladder 57, connected to a deformable annular bladder 58, normally full of liquid, placed between a shoulder 59 of the support 40 and another shoulder 60 of the support piece 45, such so that when the support 40 is in the "completely lowered" position, that is to say at the end of its travel towards the surface 7, the annular bladder 58 is crushed. The liquid is then discharged towards the bladder 57, which pushes the part

54 and the magnets 55 towards the surface 7. The magnets

55 thus immobilize the assembly carried by the chassis 1 with a view, for example, to a more detailed inspection, or else to a momentary shutdown of the propellant brushes.

The observation member 15, mounted at the end of the arm 14, is normally a television camera associated with a light source. The arm 14 can also support a dashed ultrasonic transmitter 61 in FIG. 2, or an additional brush 62 of the same type as the propellant-brushes 3, 4, but whose axis remains parallel to the surface 7. This brush is intended to treat parts which make a sharp angle, for example an angle straight, with surface 7. It can be pins anti-rolled up on the hull of a ship.

The chassis 1 can carry other accessories, either directly or via the arm 14. There is shown in FIG. 1, at the back, in dashes, a paint stencil 63.

The arm 14 can be a robotic arm, capable of taking different tools or accessories itself, stored in a store carried by the chassis. This more expensive version avoids taking the device out of the water or resorting to a charger on each change of tool or accessory.

It will be noted that the relative position of the wheels 5, 6 and the brushes 3, 4, means that the wheels are still moving on a surface which has just been brushed, and which consequently is ^ - devoid of most of its accidental roughness. _^ . The position of the stencil 63 at the rear results in the wheels not coming into contact with the freshly painted surface. ^Fig. 8 is a block diagram of the computer structure of the device.

The central control unit 19 comprises a central system 100 comprising a microprocessor and a memory, connected to a screen 101 and an instruction input keyboard 102, equipped with a remote control handle 103. On the link between the system central of a bridge, and the screen and the keyboard on the other hand, can be interposed a modulator-demodulator assembly 104 for the case where this link is at long distance.

The central system 100 is connected to an input-output selector 105, which ensures its connection with serializers-deserializers 106, 106a, which each correspond to a chassis 1, _la. The role of each serializer-deserializer is to put the signals received from the central system in the form of a series of optical signals transmitted by optical fibers or, in the opposite direction, transforming the series of optical signals transmitted from the chassis, into electrical signals usable by the central system.

An "umbilical" 20, 20a connects each serializer 106, 106a to the chassis 1, the corresponding one. Each umbilical comprises, in principle, two coaxial conduits, the inner conduit of which is used for sending working fluid (oil) to the chassis, and the peripheral conduit used for the passage of the fluid in return. In addition, two optical fibers 107, 108, are connected to the serializer-deserializer 106; the first is used for the transmission of information from chassis 1 and the second for the transmission of control signals traveling in the opposite direction.

On the chassis, inside the box 18 which contains the electronic switching and control members, there is a serializer-deserializer 109, which is the correspondent of the serializer-deserializer 106 and has the same functions, in the opposite direction.

The serializer-deserializer 109 receives, via an input interface 110, the signals from the various sensors 111 carried by the chassis. These sensors include the sensors 111 carried by the chassis. These sensors include sensors 8 to 11. The distance from the chassis 1 to the support surface 7, already mentioned, and which are preferably ultrasonic probes. They also include incremental angular sensors sensitive to the rotation of the motors 42, 44, 47 which control the wheels 5, position sensors, actuators 16, wheels 6, a relative position sensor, the arm 14 and wheels 5. They may also include an inclinometer, a pressure sensor and tactile sensors sensitive to the contact of the shockproof belt 2 with an obstacle, as well as eddy current sensors capable of detecting a weld bead in a surface of support formed of welded metal sheets.

The serializer-deserializer 109 transmits, via an output interface 112, control signals to actuators 113, carried by the chassis. Among these actuators, there are the motors 42, 44, 47 controlling the steered driving wheels 5, the motors 12 of the brush motors 3, 4. They can also include the location and lighting control of the television camera, operation of the ultrasonic generator. It will be noted that the motors having a relatively high energy consumption, and in particular those of the brush-thrusters are hydraulic motors connected by the umbilical to a pump located away from the chassis. In this case, the signals transmitted by the input 112 control electrovalves which are themselves supplied with electric current by cells or batteries on board the chassis. In the case of low consumption actuators, these are connected directly to the cells or batteries. These also supply energy to the sensors that need it. It will however be appreciated the very limited number of actuators. The signals from the television camera 114 follow a slightly different path from that of the sensors 111, because of the large amount of information to be transmitted. These signals are sent to a special serializer 115, which puts them in the form of series of signals transmitted by optical fiber. !

107, but with a different wavelength. These signals, thus shaped, pass through the optical fiber 107 but do not enter the serializer-deserializer 106, and are sent to an analysis-recording unit 116, passing through a selector 117 connected to the various umbilicals 20, 20a. The output of the analysis-recording assembly 117 is connected to a control video screen 118.

Claims

1. Apparatus for the observation and / or treatment of an immersed surface and comprising: a rigid chassis, - wheels carried by the chassis and intended to come to bear on the surface, hydraulic means, carried by the chassis and capable of exerting on it a force directed towards the surface, - at least one observation and / or treatment tool carried by the chassis, characterized in that it also comprises:

- at least one sensor sensitive to the distance of the tool from the surface; - actuation means capable of moving said tool perpendicular to the surface;

- computer means, capable of receiving signals from said sensor and of transmitting in response control signals intended for said actuating means to maintain the tool at the desired distance from the surface.

2. Apparatus according to claim 1, characterized in that the computer means are separated from the chassis and connected to the latter by a fiber optic connection means and means for transforming the signals emitted by the sensor and the control signals. in optical signals and vice versa.

3. Apparatus according to claim 2, characterized in that the computer means are common to several chassis, and operate in timeshare.

4. Apparatus according to one of claims 1 to 3, characterized in that at least some of the actuating means capable of moving the observation tool and / or the treatment relative to the surface are arranged to change the position of at least one wheel relative to the chassis.

5. Apparatus according to one of claims 1 to 4, characterized in that said actuating means capable of moving the tool comprises a stepping motor.

6. Apparatus according to one of claims 4 or 5, characterized in that said wheel is carried by an arm movable perpendicular to the surface, this arm can, on the one hand, move in a defined area to hold the tool at the desired distance from the surface, and, on the other hand, move to a position where the wheel is prevented from rolling and where the device is immobilized by a magnetic suction cup or the like coming to cooperate with the wall.

7. Apparatus according to one of claims 4 to 6, wherein, said wheel is a steerable wheel and is carried by a movable arm perpendicular to the surface and further provided with actuating means for rotating the wheel around of an axis perpendicular to the surface, characterized in that it further comprises a tool support arm, mounted for rotation on the chassis, this support arm being provided with a clutch which, when it is engaged makes the carrier arm integral with said movable arm, enables said arm to be rotated relative to the chassis by means of said wheel actuation means, and which, when disengaged, maintains said carrier arm in a position fixed relative to to the chassis.

8. Apparatus according to one of claims

1 to 7, characterized in that said hydraulic means consist of a turbine formed by a solid internal disc, an external disc pierced at its center, and blades located between these two discs, and in that means scraping, brushing _!

Or polishing the surface are carried by the outer face of the inner disc.

9. Apparatus according to one of claims 1 to 8, characterized in that the sensors sensitive to ç .. the position of the tool are mounted on the chassis, in that they are in sufficient number to allow recognition topology of the surface, and in the case of a ship's hull, identify regular flatness defects due to the presence of irons

10 rod, and in that said computer means are capable of ensuring the control and command of the movements of the device from the data of this topological recognition.

10. Apparatus according to one of claims 15 1 to 9, characterized in that it is equipped with sensors capable of detecting the welds of a ship's hull by eddy currents, and in that said computer means are capable of ensure the control and command of the movements of the device using the 2 _Q data provided by said sensors.

11. Apparatus according to one of claims 1 to 10, characterized in that it is equipped with an ultrasonic transmitter capable of destroying a microbial veil which has developed on the surface.