Patent Description:
Complex systems are used in a number of areas of technology. They are complex in that they include both moving and static parts. In power generation, complex systems include turbines and engines. Electrical equipment is being more commonly used in power generation systems. Part of the reason for this is that engineers are looking for ways of reducing emissions of carbon dioxide; this is especially true in propulsion systems where fossil fuel-based combustion engines are being replaced with electrical motors connected to battery packs.

Electrical power for vehicular systems is seen to be a greater part of future designs as the technology develops. However, one of the issues with using electrical power, rather than the combustion of fossil fuels, is that electrical power requires new methods to test, probe and repair electrical motors. This is because gaps between components in electrical motors tend to be much smaller than they are in combustion engines. Furthermore, many other systems, such as nuclear power, oil and gas production and telecoms systems have complex systems that are located within confined spaces. Consequently, the requirements for in situ repairs are much more complex as the classical tools that have been used for testing and repairing older systems are often not suitable for these complex systems.

In the electrical field for example, one area in which there can be problems is in the detecting, monitoring and repairing of faults on or near a rotor or a stator. Conventional borescope and robotic inspection devices are often too large to fit in the gaps between components.

<CIT> discloses a portable capacitance mapping tool for in situ field stator bar insulation capacitance mapping. The capacitance mapping tool consists of an improved capacitance probe head assembly that has an inflatable electrode bladder mounted at the end of a telescoping support pole that is provided for enabling a service technician to accurately position the probe head assembly between stator bars of a large electric motor or power generator from a remote location. Using the tool, capacitance measurements of insulation on stator bars can be obtained without removing the field. The tool is constructed such that it can be inserted between the field generating component (e.g., the rotor) and the stator windings of a large motor or power generator, thus, precluding the need for field removal. A bendable articulated tip section, which remains in a particular bend arrangement until manually reconfigured, is provided at one end of the tool where the capacitance measuring probe head is attached. This allows the probe head to be, preconfigured at a particular angle with respect to the support pole and the stator bars prior to inserting. The probe head includes a bladder support plate which acts as a spacer and is adapted to accept one or more additional spacer plates for changing the overall width of the probe head to adjust for different spacings between stator bars. The pole supports an electric cable from the probe electrode to a remote electric meter and an air hose to a remote fluid source for inflating/deflating the probe bladder.

United States patent <CIT> discloses an inflatable capacitance test device for measuring the capacitance of the insulation wrap on armature bars in electromagnetic generators and motors. The test device has a probe that has an electrode plate mounted on an inflatable bladder. The plate is formed of an elastomeric conductive material and is sufficiently flexible to make good surface contact with the insulation on an armature bar. The plate is electrically connected to a capacitance meter that is also coupled to ground as are the armature bars during testing. The bladder is initially deflated to reduce the thickness of the test device so that the device can be slid into the narrow gap between the insulated armature bars of a stator. Once positioned between the bars, the bladder is inflated with a pressure hose to press the electrode plate firmly against the surface of the insulation of the armature bar. Once the capacitance of the insulation has been measured, the bladder is deflated with the aid of a vacuum pump to minimize the width of the probe.

There is a need for new robotics systems that can deliver a robotic probe to a required area within a complex system, e.g. an electrical motor, to perform a test or repair and if required to move a probe or tool within a confined space to effect that test or repair, without damaging other components of the system, e.g. rotors, stators, windings or contacts or wires within the system. In other words, new designs for robotics need to be developed to overcome the limitations of conventional tools for testing and repairing machinery.

In a first aspect there is provided an inflatable probe as set out in claim <NUM>.

In some embodiments a second seal electrode are provided around the external surface of the balloon and the sealing plug, so as to seal the balloon against the sealing plug, and the second seal electrode is provided with an electrical contact to connect to the outer electrode.

In some embodiments each inner electrode and each outer electrode are flexible electrodes.

In some embodiments each internal electrode is formed of at least one of graphene, carbon nanotubes, and metallic nanotubes.

In some embodiments there may be from <NUM> to <NUM> pairs of inner electrodes and outer electrodes.

In some embodiments there are a plurality of parallel arranged inflatable balloons each with separate pairs of inner electrodes and outer electrodes to enable positioning of the sensor relative to the component of interest.

In some embodiments the at least one tool is one or more of a charge-coupled device, a complementary metal-oxide semiconductor chip, a Hall effect sensor, and a grabbing implement.

In some embodiments the first wire that is connected to the first seal electrode and a second wire that is connected to the second seal electrode are coupled to control voltage sources to provide a controlled supply of voltage to the at least one electrode pair.

In some embodiments a voltage supply is connected to a computer to control the supply of voltage to the at least one electrode pair, the computer also being used to receive signals from the inflatable probe.

In some embodiments a conduit is provided in the sealing plug for supplying fluid and removing fluid from the balloon.

In a second aspect there is provided a method of testing a component using the inflatable probe of the first aspect as set out in claim <NUM>.

In some embodiments the inflatable probe is moved by applying controlled voltages to the electrodes of the balloon.

In some embodiments the inflatable probe is moved to different locations with respect to the component for further testing or to a different component of interest for testing before the inflatable probe is removed from the workspace.

In some embodiments the workspace is an engine.

The following table lists the reference numerals/signs used in the drawings with the features to which they refer:.

<FIG> is a schematic perspective view of a first embodiment of an inflatable probe of the present invention in the form of a dielectric elastomer balloon. In this a balloon <NUM> is provided (e.g. coated) with a compliant inner electrode (<NUM>) and an outer electrode <NUM>. The inner electrode is positioned on the inside surface of the balloon <NUM>, whilst the outer electrode <NUM> is positioned on the outside of the balloon <NUM>. In <FIG> the balloon <NUM> is in an inflated state and contains a fluid e.g. a liquid or air. The fluid is sealed in the balloon using a sealing plug <NUM> that is position in a neck <NUM> of the probe. The sealing plug <NUM> provides a first seal electrode <NUM>, which is used to engage with the inner electrode within the balloon <NUM>, and has a wire 15a that is connected to the first seal electrode and passes through the sealing plug <NUM>. The sealing plug <NUM> also has a second seal electrode <NUM> that is positioned around the outside of the sealing plug <NUM>. In <FIG> the second seal electrode <NUM> in the form of a clip that forms around the balloon <NUM>. The clip, which may be made of any suitable material, acts both as the second seal electrode for connecting with the outer electrode <NUM> on the surface of the balloon <NUM> and a clamp to hold the balloon <NUM> onto the sealing plug <NUM>. <FIG> shows a wire 16a leading from the clip <NUM>. The wire 16a is used to provide a voltage to the second seal electrode <NUM> and thus to the outer electrode <NUM> on the balloon. The balloon <NUM> itself is formed of a dielectric material, which may for example a rubber or latex or other deformable dielectric material. The inflatable probe has a tool <NUM> located on the balloon opposite the neck <NUM>. There may be any suitable number of tools <NUM> positioned about the balloon <NUM>. The tool <NUM> may be any suitable inspection tool or sensing device. For example the tool <NUM> may be a charge-coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) chip for component inspection including non-destructive evaluation, or a Hall effect sensor for assessing magnetic field quality, or a grabbing implement for removal of foreign object damage. In <FIG> the tool <NUM> is a charge-coupled device (CCD) housed in a sensor head for digitally imaging components for non-destructive evaluation.

<FIG> is a schematic cut-away image of the inflatable probe shown in <FIG> shows the inner electrode <NUM> of the inflatable probe <NUM> that is provided (e.g. coated) on the inside surface of the balloon <NUM> with the outer electrode <NUM> being provided on the outside surface of the balloon <NUM>. The sealing plug <NUM> is also shown in the neck <NUM> of the balloon <NUM>. The sealing plug <NUM> forms an airtight seal with the deformable dielectric material of the balloon <NUM>. The first seal electrode is used to supply the voltage to the inner electrode <NUM> on the inner surface of the balloon <NUM> whilst the second seal electrode <NUM> provides the voltage to the outer electrode <NUM> on the outer surface of the balloon.

<FIG> is a schematic close-up view of the electrode structure of the probe of <FIG>. The balloon <NUM> is formed of a deformable dielectric material, e.g. a latex. Coating the outer/external surface of the balloon <NUM> is the outer electrode <NUM>. Coating the inner/internal surface of the balloon <NUM> is the inner electrode <NUM>. As the balloon <NUM> is formed of a deformable dielectric material, it will stretch or decrease in size depending upon whether the balloon is inflated or deflated and the electrodes must also be able to stretch and deform with the dielectric material that they are formed around. If the inner electrode <NUM> and the outer electrode <NUM> are not able to deform they may well damage or break the balloon <NUM>.

The electrodes may be made from any suitable deformable conducting material. In particular, this may a flexible host or matrix doped with materials such as graphene, carbon nanotubes, metallic nanotubes. Such coatings may be applied as a spray with a spray gun and then heated to cure. If the electrode and dielectric material are both made of a rubber, the adhesion between them and the rubber/latex balloon will be strong. Alternatively, it may be made from another suitable conductive polymer coated onto the inner or the outer surface of the balloon <NUM>. Alternatively, it may be made of any other deformable electrode. The use of electrodes about a layer of flexible dielectric material means that this area of the balloon acts as an actuator. As such, the application of a voltage to the electrodes creates a pressure within the layer of flexible dielectric material and results in deformation of the shape of that layer. This deformation causes an extension/inflation or compression/deflation of the balloon. By attuning the electrode structure around the dielectric elastomer balloon allows for controlled deformation such that the actuator can be manipulated in shape.

<FIG> is a schematic close-up perspective view of the electrode structure of the inflatable probe <NUM> shown in <FIG>, more particularly the portion on and around the sealing plug <NUM> of the probe. The sealing plug <NUM> is used to maintain the volume of fluid within the balloon <NUM>. The fluid may be a gas such as air, nitrogen, or a gas lighter than air such as helium. The sealing plug <NUM>, which includes the first seal electrode <NUM>, may be made from a solid material, e.g. a metal. The second seal electrode <NUM> may be provided on the sealing plug <NUM>. Alternatively, as presented in <FIG> the second seal electrode <NUM> may be formed on a clip that also has a purpose to keep the balloon <NUM> attached to the sealing plug <NUM>. The clip may be formed of any suitable material, e.g. a metal, a plastics material or a composite material. The second seal electrode <NUM> for contacting the outer electrode <NUM> on the balloon <NUM> is typically made from a solid material, e.g. a metal such as copper, which may be a copper strip. The advantage of using solid materials for the electrodes is that it allows for wire cables to be used, these can be easily connected to the electrodes. It also allows for easier connection with the balloon <NUM> that has a low surface energy.

<FIG> presents a close-up of the electrical connections within the inflatable probe <NUM>. In <FIG> the balloon <NUM> is shown with the inner electrode <NUM> mounted on the inner surface of the balloon <NUM> and the outer electrode <NUM> mounted on the outer surface of the balloon <NUM>. The sealing plug <NUM> with the first seal electrode <NUM> is shown abutting the inner electrode <NUM> of the balloon <NUM>. The clip containing the second seal electrode <NUM> is shown contacting the outer electrode <NUM>. In <FIG> the first wire 15a and the second wire <NUM> are shown to connect with the first seal electrode <NUM> and the second seal electrode <NUM> respectively. In this embodiment the first wire 15a is the negative wire and the second wire 16a is the positive wire. In this case the use of the clip for the second seal electrode <NUM> is beneficial as it imparts a force onto the balloon <NUM> and maintains the contact between the first and second seal electrodes and the inner and outer electrodes that are on the balloon <NUM>. The sealing plug <NUM> may also have a conduit attached that allows for the inflation and deflation of the balloon at appropriate times.

<FIG> is a schematic perspective view of a second embodiment of an inflatable probe <NUM> of the present invention. In this embodiment the balloon <NUM> is shown having a plurality of outer electrodes <NUM> positioned around the outer/external surface of the balloon <NUM>. Each outer electrode <NUM> is separated from the neighbouring outer electrode <NUM> by a non-conducting area <NUM>, which area is not covered with the electrode material. The position of the inner electrodes (not shown) on the inner/internal surface of the balloon <NUM> corresponds with the position of the outer electrodes, i.e. they are located on the opposing surface of the balloon <NUM>. The sealing plug <NUM> has a number of first seal electrodes that connect with the positions of the inner electrodes. Each of these electrodes may have their voltage supplied by its own wire. Alternatively, the electrodes may have the voltage supplied through a single wire or they may be paired up to reduce the number of wires. The number of second seal electrodes on the sealing system, whether on the plug, clip or other sealing mechanism will be the same as the number of outer electrodes <NUM>. Each of these are solid electrodes which pair with the outer electrodes. Similar to the first seal electrodes the second seal electrodes may be supplied by any suitable number of wires from a single wire, electrodes matched in groups to each electrode having its own wire. At the head of the probe is shown a tool <NUM>. In <FIG> the tool <NUM> is a complementary metal-oxide semiconductor (CMOS) chip housed in a sensor head for digitally imaging components for non-destructive evaluation. There may be any suitable number of tools <NUM> positioned about the balloon <NUM>. The tool <NUM> may be any suitable inspection tool or sensing device. For example the tool <NUM> may be a charge-coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) chip for component inspection including non-destructive evaluation, or a Hall effect sensor for assessing magnetic field quality, or a grabbing implement for removal of foreign object damage. The response from the tool at the tip of the inflatable probe may be transmitted via electrical wires, optical fibres, or wireless methods such as Bluetooth® or Wi-Fi™ to the outside of the complex component under investigation.

By controlling the voltage to the electrodes, which are separated by the dielectric medium of the balloon, causes a deformation of the balloon about the electrode. The deformation of the balloon is a result of the forces acting upon it. When voltage is applied to the electrodes, an electric field is established within the thin dielectric layer of the balloon. The electric field causes Compressive Maxwell stress within the dielectric material of the balloon. This causes a reduction in the thickness of the dielectric material but an increase in the area of the dielectric material. Therefore, through the application of voltage it is possible to control the deformation of the balloon probe and thus allow it to move. By using a number of electrodes around the probe, the probe is able to move with a number of degrees of freedom. The balloon probe works by controlling the voltage to the electrodes so that the probe is able to move within a confined space to a point to sense or probe the system. In the case of a single electrode pair the balloon probe can crawl through the space, with more than one electrode pair the balloon can walk by expanding one electrode area whilst maintaining the other at the same length and repeating for the other electrode pair. The greater the number of electrode pairs and the more control that the system can have. However, the increase in the number of electrode pairs also increases the complexity of the system.

The probe can be inserted into the component to be inspected in an inflated or non-inflated state depending upon the size of the aperture. Once into a space the pressure within the balloon may be controlled by the addition or removal of a fluid. This allows the probe to either be able to slide through a gap with minimal contact with the walls or to crawl into a space if the balloon cannot be slid into the appropriate position. If the balloon is slid into position the balloon may be inflated so that contact with the component is maintained and inspection using the probe can take place. Although, this is described as slid, it may also apply to be floated into position if the fluid used is lighter than air. Changing the fluid as the balloon probe moves within the complex environment can assist the balloon to move through more complex environments.

<FIG> presents a flow chart at the operation of the probe of the present invention in a method <NUM> of testing a component. In Step <NUM> the device is inserted into the working space. Access to the workspace may be through an access port, like a borescope port or similar, or the casing of the complex component may be removed or if there is small external access then the probe may be inserted through that access. With the probe inside the complex component the probe can be moved and positioned to a point that is of interest in Step <NUM>. The number of electrode pairs on the balloon will determine in which planes it is possible to move the probe. In the case of a single electrode pair the probe will only be able to move in a single plane. If there are more electrode pairs then the number of planes that the balloon can move in increases so that it can access more difficult to reach regions of the component. The pressure in the balloon may be changed during the positioning step. This allows the balloon to move more easily and to reach narrower and more difficult to reach parts that are not accessible by other means. In Step <NUM> the testing using the sensor takes place. The testing may be to inspect for degradation of components or inclusion of foreign object debris in the electrical machine, or to non-visually assess the health of the asset such as through a Hall effect sensor to study the magnetic field quality. Depending upon the nature of the tests the balloon may be inflated to fill the cavity/volume that is being inspected. Inflation of the balloon may help to position the sensor against the size of the component within the cavity/volume. Once the testing has been performed the balloon may be moved to a second location. This may be done by moving the device using any cables. Alternatively, controlled voltage may be applied to the inner and outer electrodes on the balloon. By applying the controlled voltage allows the balloon to move itself within the space by crawling its way along at least one of the surfaces of the cavity/volume. Once the balloon is moved into the second or further desired location the sensor may perform more tests to build up a map or an image of the desired properties of the scan area of the component. Once the desired number of tests have been performed within the desired area of the component the balloon probe can be removed from the component - Step <NUM>. Depending upon the nature of the area that has been probed the balloon may be inflated or deflated as appropriate and the electrodes activated if required so that the probe is able to crawl out of the area and then removed through the insertion hole.

Claim 1:
An inflatable probe (<NUM>, <NUM>) for testing a component, the inflatable probe comprising:
a balloon (<NUM>, <NUM>) formed of a dielectric material, the balloon having a neck (<NUM>) and at least one electrode pair comprising an inner electrode (<NUM>) and an outer electrode (<NUM>), the inner electrode (<NUM>) being positioned on an internal surface of the balloon (<NUM>, <NUM>) and the outer electrode (<NUM>) being positioned on an external surface of the balloon (<NUM>, <NUM>);
a sealing plug (<NUM>, <NUM>) that forms an air tight seal with the neck (<NUM>) of the balloon (<NUM>, <NUM>) to retain a fluid within the balloon, the sealing plug (<NUM>, <NUM>) at least having a seal electrode (<NUM>) to connect to the inner electrode (<NUM>) within the balloon, the sealing plug supporting a first wire (15a) to connect to the first seal electrode (<NUM>); and
at least one tool (<NUM>, <NUM>) that is connected to the balloon (<NUM>, <NUM>).