GB2187689A

GB2187689A - Vehicle for movement on surface of any orientation

Info

Publication number: GB2187689A
Application number: GB08606055A
Authority: GB
Inventors: Brian Frank Chapman; William Stephen Groves; Dudley Robin Medhurst; John Sutton
Original assignee: Central Electricity Generating Board
Current assignee: Central Electricity Generating Board
Priority date: 1986-03-12
Filing date: 1986-03-12
Publication date: 1987-09-16
Also published as: GB8606055D0

Abstract

A vehicle (1) has a body (3, 4) carrying tracked wheels (5, 6) and permanent magnets (10) whereby the vehicle can move over any magnetic material surface (2) irrespective of the orientation of the surface (2). <IMAGE>

Description

SPECIFICATION Vehicle This invention relates to a vehicle, and particularly to a vehicle for use in the remote inspection of structures such as electrical generator stators, nuclear reactors, storage tanks and pipes, and the like.

It is often necessary to inspect the surface of a structure at locations inaccessible to people, and thus there is a need for a vehicle capable of traversing such surfaces while carrying inspection devices, with information obtained by the inspection devices being transmitted to a remote point from which the vehicle is controlled.

Surfaces to be inspected can be at any orientation and thus there is a need for a vehicle capable of moving over a surface while being held in relation to that surface.

According to this invention there is provided a vehicle comprising a body, means to support the body for movement over a magnetic material surface, and magnet means carried by the body to be in spaced relation to said surface while providing an attractive force capable of retaining the vehicle and a load carried thereby, on said surface with any orientation of said surface.

The vehicle of this invention has the advantage that the magnet means serves to provide an attractive force which holds the vehicle against a surface over which it isto move, and thus surfaces at any orientation, for exam ple vertica I su rfaces, or the underside of horizontal surfaces, orthe inside of curved surfaces, can be traversed by the vehicle.

The support means can comprisewheelscarried bythe body, or a pairoftrack members running on wheels carried by the body.

The body can carry drive means, for example one or more electric motors, energisabletoeffectthe movement of the vehicle o r the surface.

The vehicle can include sensor means operative to effect automatic control of the direction of movement of the vehicle over the surface.

Otherwise thevehicle can be adapted and arranged for remote control.

Avehicle according to this i,^,-ven.iori 'will now be described by way of exa m p e wiii, reference to the diagrammatic drawings, in which Figure lisa perspective view of the vehicle on a surface being inspected; Figure2 is a plan view of the vehicle; Figure 3 is a longitudinal sectional view on the line lil - lil in Figure 2; and Figure4is a sectional viewofthe iine IV - IV in Figure 2 and illustrating the operation of the magnet means of the vehicle.

Figure 1 showsthevehicle 1 as it is moving over the surface of the bore of an electrical generator stator, the vehicle 1 being located substantially atthe top of the bore. The bore surface is defined by a plurality of longitudinally extending spaced parallel teeth 2, the vehicle 1 moving along these teeth 2 as it moves over the surface.

The vehicle 1 comprises a body formed buy a pair of magnetic material, for example steel, side members 3 held spaced laterally ofthe longitudinal axis ofthe vehicle by a connecting bridgemember4of non-magnetic material, for exam pie plastics material.

Each side member 3 carries three wheels 5 about which runs atoothed track member 6. As shown in Figure3,thetrack members 6 engagethe surface 2 over which the vehicle 1 isto move and supportthe vehicle 1 relative thereto with the side members 3 spaced from the surface 2.

Each side member 3 also carries drive means in the form ofan electric motor 7 which, by way of a reduction gear box 8, drives a drive pinion 9 which engages the associated track member 6 such asto hold it taut. Thus, operation of the electric motors 7 will cause movement of the track members 6 and thus movement of the vehicle 1 over the surface 2.

Mounted on each side member3 are magnet means comprising two rows of permanent ferrite magnets 10 one row on each side of the wheels 5 carried by that side member 3. The rows of magnets 10 extend longitudinally of the vehicle 1, and as shown in Figure 4the magnets 10 of one row on each side member3 present polefaces of one polarity in the direction towards the surface 2 while the magnets 10 ofthe other row on that side member3 present pole faces of the other polarity towards the surface 2. As clearly shown in Figure 3, the vehicle 1 is supported overthe surface 2 such asto leave an air gap between the surface 2 and thefacing pole faces of the magnets 10 whereby the vehicle can move over the surface 2 while being held there against by the magnetic forces provided bythe magnets 10.

As shown in Figure 2, the spacing between the side members 3 of the vehicle 1 is such that each side member 3 and the track member 6 and magnets 10 carried thereby travels over a respective one of the teeth making up the surface 2.

Figure 4 shows the magnetic circuit which exists at each side of the vehicle 1,the magnets 10 of the two rows being magnetically coupled bytheside member 3with lines of flux extending from the magnets 10 ofone row through the associated air gap through the tooth 2, and through the associated airgapto the magnets 10 ofthe other row. Thetwo rows of magnets 10 on each side member 3 are spaced flom each other such that there is a relatively Iargeairgapbetweentheirexposed polefacesas compared with the air gap between the polefaces and the surface 2 whereby the attractive force between the magnets 10 and the surface 2 is high.

The magnetic forces thus provided are sufficientto retain the vehicle 1, and a load (not shown) carried thereby, on the surface 2 irrespective ofthe orientation of the surface 2, for example on the underside of a surface as shown in Figure 1. The side members 3 are designed to be as light as possible while having a sufficiently low impedance to the magnetic flux to ensure sufficient attractive force between the vehicle 1 and the surface 2.

Mounted at each corner of the vehicle 1 on the magnetic pole face thereat, is a magneto-resistance probe 11 sensitive to the magnetic flux at that position, these probes being connected in control circuitryforthe electric motors 10. If during its movement along two teeth 2 as shown in Figure 2, the vehicle deviates from the correct path, the magnetic field sensed by one of the probes 11 at the leading end of the vehicle is reduced since the probe 11 will no longer be located over the associated tooth 2. This reduces the electrical resistance of the probe 11 and an error control signal is generated and fed to the electric motor control circuitry. The error control signal causes the speed of the appropriate one or both of the electric motors 10 to be changed thereby to return the vehicle 1 to the correct path of movement.The control circuitry can be carried by the vehicle and thus the probes 11 will be operative to effect automatic control of the direction of movement of the vehicle 1 over the surface 2, the only supply to the vehicle necessary being the supply of powerforthe electric motors 10, this by wayofa cable 100.

Although the vehicle described above is shown moving over a surface constituted by a plurality of teeth, vehicles in accordance with the invention can otherwise be used on continuous flat surfaces, in which case an automatic guidance system as described above cannot be used. For such usea remote control guidance system can be provided,for example a joystick or other type of controller coupled tothevehicle byacable.

In usethevehiclewould carry an inspection device, for example a coil serving to detect damage to the laminations of the stator core shown in Figure 1, an ultrasonic or radio frequency probe for testing winding insulation or a television camera for carrying out a visual inspection, signals from the inspection device being transmitted from the vehicle to a control station.

Claims

1. Avehicle comprising a body, meansto supportthe body for movement over a magnetic material surface, and magnet means carried by the body to be in spaced relation to said surface while providing an attractive force capable of retaining the vehicle and a load carried thereby, on said surface with any orientation of said surface.

2. Avehicle as claimed in Claim 1, in which the body comprises a pair of magnetic material side members held spaced laterally ofthe longitudinal axis of the vehicle by a bridge member of non-magnetic material.

3. Avehicle as claimed in Claim 2, in which the magnet means comprises two rows of permanent magnets carried by each of said side members ofthe body, the rows extending longitudinally of the vehicle with the magnets of one row on each side member presenting pole faces of one polarity in the direction to betowards said surface and the magnets of the other row on that side member presenting pole faces of the other polarity in said direction.

4. Avehicle as claimed in any preceding claim, in which said support means comprises wheels carried by said body.

5. Avehicle as claimed in any one of Claims 1 to 3, in which said support means comprises a pairof track members running on wheels carried by said body.

6. Avehicle as claimed in Claim 4 or Claim 5 as dependent upon Claim 3, in which said wheels are carried by said side members between said rows of magnets thereon.

7. Avehicle as claimed in any preceding claim, in which the body carries drive means energisable to effect said movement of the vehicle over said surface.

8. Avehicle as claimed in Claim 7 as dependent upon Claim 5, in which said drive means comprises two electric motors each arranged to drive a respective one of said track members, the electric motors being independently controllable thereby to effect steering of the vehicle over said surface.

9. Avehicle as claimed in any preceding claim, including sensor means operative to effect automatic control ofthe direction of movement of the vehicle over said surface.

10. Avehicleasclaimed in Claim 9, in which said sensor means functions magnetically and is responsive to discontinuities in said surface.

11. Avehicle as claimed in Claim 10, in which said sensor means comprises magneto-resistance probes arranged at each side at both ends of the vehicle.

12. Avehicle as claimed in Claim 11 as dependent upon Claim 8, in which said magneto-resistance probes provide output signals used to control said electric motors to effect steering of the vehicle.

13. Avehicle as claimed in anyone of Claims 1 to 8, adapted and arranged for remote control.

14. Avehicle substantially as hereinbefore described with reference to the drawings.