Deformation and configuration sensing

Abstract

A computer implemented method (figure 3, 300) includes receiving data indicative of propagation of magnetoinductive or electroinductive waves in a magnetoinductive or electroinductive waveguide (figur

Description

BACKGROUND

[0001] There are many applications in which sensing a configuration of an object is desirable or necessary. For example, configuration sensing may be used in robotics, human-machine interfaces, strain sensing, etc.

[0002] In controlling a limb of a robot, for example, determining the actual configuration of the limb can provide improved control. In some cases, the degree of actuation of each of the limb's actuators may be used to infer the configuration of the limb.

[0003] A configuration of an object may be sensed using a combination of magnets and hall sensors. Magnets and corresponding Hall sensors may be attached to various parts of the object, and the Hall sensors may be used to determine the relative positions of the magnets and Hall sensors. BRIEF SUMMARY

[0004] In an aspect, a computer implemented method comprises: receiving data indicative of propagation of magnetoinductive or electroinductive waves in a magnetoinductive or electroinductive waveguide, the waveguide including a plurality of resonator elements; and determining, based on the received data, information indicative of a configuration of the waveguide.

[0005] According to an embodiment, at least one of: the determining includes obtaining, from the received data, time-domain data indicative of reflected magnetoinductive or electroinductive waves, and determining the deformation based, at least in part, on the timedomain data; and the determining includes obtaining, from the received data, frequency-domain data indicative of a input scattering parameter spectrum of the magnetoinductive or electroinductive waves, and determining the deformation based, at least in part, on the frequency-domain data.

[0006] In an embodiment, determining the deformation based on the frequency-domain data includes determining frequencies corresponding with peaks or troughs in the input scattering parameter spectrum.

[0007] Determining the deformation may include determining one or more frequency shifts, relative to a input scattering parameter spectrum of a reference configuration, of the peaks or troughs in the input scattering parameter spectrum.

[0008] In an embodiment, the method further comprises at least one of: detecting an object proximate to the waveguide, based on the received data; detecting damage to the waveguide, based on the received data; filtering the received data, prior to determining the information indicative of the deformation, to remove features of the data associated with at least one of power or data carried via the waveguide to be provided to or from a component external to the waveguide; omitting, from data used in the determining, a frequency range associated with at least one of power or data carried via the waveguide to be provided to or from a component external to the waveguide; and selecting, for use in the determining, data indicative of propagation of magnetoinductive or electroinductive waves in the waveguide that corresponds to a time window during which at least one of data or power transfer with components external to the waveguide is suspended.

[0009] In an embodiment, first and second resonator elements of the plurality of resonator elements are respectively associated with first and second portions of a robot, wherein the first and second portions are movable with respect to each other such that relative movement of the first and second portions causes deformation of the waveguide.

[0010] In an embodiment, first and second portions are included in a part of the robot that is: a soft robotics component of the robot, an articulated soft robotics component of the robot, a continuum soft robotics component of the robot, a rigid robotics component of the robot, a robotic limb driven by hydraulic or pneumatic actuators, or a compliant mechanism.

[0011] An aspect provides computer readable instructions that, when performed by a processing device, cause the processing device to carry out a computer implemented method as described herein.

[0012] As aspect provides a computer readable storage medium storing instructions that, when performed by a processing device, cause the processing device to carry out a computer implemented method described herein.

[0013] An aspect provides a processing device arranged to determine a configuration of a deformable object, the device comprising: memory circuitry to store instructions; and

[0014] processing circuitry to perform the instructions, wherein the instructions are to cause the processing circuitry to: receive data indicative of propagation of magnetoinductive or electroinductive waves in a magnetoinductive or electroinductive waveguide, the waveguide including a plurality of resonator elements, the plurality of resonator elements including at least first and second resonator elements, the first and second resonator elements are arranged to change their relative pose when the configuration of the deformable object is changed, wherein the relative pose describes at least one of (i) relative positions of the first and second resonator elements, and (ii) relative orientations of the first and second resonator elements; and determine, based on the received data, information indicative of the configuration of the deformable object.

[0015] An aspect provides a robotic component comprising: a first portion; a second portion, the second portion moveable relative to the first portion; and a pose sensor, the pose sensor comprising: a magnetoinductive or electroinductive waveguide comprising a plurality of magnetoinductively or electroinductively coupled resonant elements, the resonant elements including a first resonant element and a second resonant element, the first resonant element arranged to move with the first portion and the second resonant element arranged to move with the second portion.

[0016] In an embodiment, the robotic component further comprises an input component and a receiver component, the input component to supply at least one of power and data to the waveguide, and the receiver component to receive the at least one of power and data via the waveguide.

[0017] In an embodiment, the robotic component is selected from: a complaint mechanism, a soft robotic limb, a articulated soft robotic limb, a continuum soft robotic limb, a rigid robotic limb, or a robotic limb driven by hydraulic or pneumatic actuators.

[0018] In an embodiment, the robotic component further comprises processing circuitry arranged to receive data describing propagation of magnetoinductive or electroinductive waves in the waveguide and to determine a pose of the robotic component based on the received data.

[0019] In an aspect, a method of producing a configuration sensor for a robot, the method comprises: providing, a first resonant element that is arranged to move with a first portion of the robot, the first resonant element being a resonant element of a magnetoinductive or electroinductive waveguide of resonant elements; and providing a second resonant element that is arranged to move with a second portion of the robot, the second resonant element being a resonant element of the waveguide of resonant elements, wherein magnetoinductive or electroinductive coupling between the first and second resonant elements is dependent on a relative pose of the first and second elements. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0020] Examples of the invention are further described hereinafter with reference to the accompanying drawings.

[0021] FIG. 1A illustrates an example of a magnetoinductive waveguide.

[0022] FIG. IB illustrates an example of an electroinductive resonator.

[0023] FIG. 1C illustrates an example of an electroinductive waveguide.

[0024] FIG. 2A illustrates an example of a deformable object that includes a waveguide.

[0025] FIG. 2B illustrates another view of the deformable object of FIG. 2A.

[0026] FIG. 2C illustrates another view of the deformable object of FIG. 2A and FIG. 2B.

[0027] FIG. 2D illustrates a waveguide having electroinductive resonators.

[0028] FIG. 3 illustrates a method according to some examples.

[0029] FIG. 4 illustrates an example plot of frequency domain data that may be obtained from the waveguide of FIG. 2A to FIG. 2C.

[0030] FIG. 5 illustrates a plot illustrating the effect of bending the waveguide on the input scattering parameter spectrum.

[0031] FIG. 6A illustrates a simulation of frequency dependence of impedance with bend angle in the arrangement of FIG. 2A to FIG. 2C.

[0032] FIG. 6B illustrates another arrangement for the waveguide.

[0033] FIG. 6C illustrates another arrangement for the waveguide.

[0034] FIG. 6D illustrates another view of the waveguide of FIG. 6B or FIG. 6C.

[0035] FIG. 6E illustrates a simulation of frequency dependence of impedance with bend angle the waveguide of FIG. 6B, FIG. 6C, or FIG. 6D.

[0036] FIG. 7A illustrates an alternative resonator.

[0037] FIG. 7B illustrates an alternative resonator.

[0038] FIG. 8 illustrates another example of a waveguide.

[0039] FIG. 9A illustrates another example of a waveguide.

[0040] FIG. 9B illustrates another example of a waveguide.

[0041] FIG. 9C illustrates another example of a waveguide.

[0042] FIG. 10A illustrates an example of a waveguide with a nearby object.

[0043] FIG. 10B shows the resonant frequencies of the waveguide of FIG. 10A.

[0044] FIG. 11 illustrates a device according to some examples.

[0045] FIG. 12 illustrates a method according to some examples. DETAILED DESCRIPTION

[0046] Deriving a configuration of an object from degrees of actuation of actuators can be unreliable. For example, if movement of the object is obstructed the actual movement may be less than would be inferred from the actuator. Further, in the case of a compliant mechanism, such as a soft robot, deriving the configuration of the mechanism from the actuators can be challenging, and may be particularly inaccurate when movement of the mechanism is obstructed.

[0047] Using magnets to detect the configuration of an object can lead to difficulties when magnetic or ferrous materials are present in the environment of the object. For example, a magnetic sensing arrangement may be inappropriate for a robot intended for use in ferrous pipes, since the magnet may be attracted to the walls of a pipe that the robot is traversing.

[0048] Furthermore, some methods of configuration sensing may involve multiple sensors, each providing a respective signal output. Each signal output must be transported to a suitable receiver (such as a processor programmed to determine the configuration). Accordingly, multiple wires or wireless communication circuits may be needed, which can increase cost and complexity, and may reduce reliability.

[0049] Examples described herein may address one or more of these limitations.

[0050] A magnetoinductive waveguide consists of an array of magnetically coupled resonators that is capable of supporting a propagating electromagnetic wave whose principle components are currents circulating in each resonator and their shared magnetic flux. Such waves have become known as magnetoinductive waves. No physical contact is needed between the resonators in order to support the magnetoinductive wave. A magnetoinductive waveguide is an arrangement in which a magnetoinductive wave can propagate (e .g. Shamonina, E., et al. "Magnetoinductive waveguide. "Electronics letters 38.8 (2002): 371 -373). A magnetoinductive waveguide includes an array of resonant elements, which may also be referred to as resonators, resonator elements, or meta-atoms. Each resonator may include a resistance, an inductance, and a capacitance in order to form a resonant circuit. FIG. 1A shows an example of a magnetoinductive waveguide 100 that includes resonators 102, shown as 102a, 102b, 102c, 102d, 102e in FIG. 1A. In the example of FIG. 1A, each resonator 102 is formed of a conductive trace m the shape of a broken loop. The capacitive gap 104, which forms the break in the loop provides capacitance, the shape of the loop provides inductance, and the material of the trace provides resistance. The structure of the resonators 102 is not particularly limited. For example, the shape may be square, as shown in FIG. 1 A, circular, etc. Further, the resonator 102 may include a spiral, or may be non-planar, e.g., by having elements on top and bottom surfaces of a substrate, or by having elements on different layers of a stacked substrate, with different surfaces or layers being connected with vias, for example. The resonators 102 may include resistive, capacitive or inductive components. The resonators 102 may be provided independently of a substrate. For example, the resonators 102 may be self-supporting, instead of being provided on a substrate.

[0051] Magnetoinductive waveguides can be used to carry data, power or both. However, the coupling between resonators is affected by the relative orientation of the resonators. As such, deformation of the array (e.g., due to bending of a substrate) can reduce the effectiveness of the waveguide. For example, in some examples a bandwidth of the waveguide may be reduced when the resonators of the array are not maintained in the same plane. For this reason, magnetoinductive waveguides may be designed to avoid or prevent such deformation of the substrate, or to mitigate the effect of bending, e.g., by using small, closely placed resonators that are less sensitive to deformation-induced bandwidth reduction.

[0052] In examples described herein, the normally undesirable effects associated with deformation of a magnetoinductive waveguide may be used to measure, or characterize, the deformation. In examples, a signal indicative of the deformation along the extent of the waveguide may be carried by the waveguide itself, and so information relating to the deformation at various points along the waveguide can be carried to an output of the waveguide without additional signal wiring. Similarly, power may be provided to the waveguide at a single input (e.g., at, or close to, one end of the waveguide), so wiring may be reduced compared with an arrangement having multiple powered sensors. Further, the waveguide may provide information regarding deformations along its length without the need for additional sensors (e.g., individual sensors for each joint of a robotic limb).

[0053] Electroinductive waveguides are described in M. Beruete, F. Falcone, M. J. Freire, R. Marques, J. D. Baena; Electroinductive waves in chains of complementary metamaterial elements. Appl. Phys. Lett. 20 February 2006; 88 (8): 083503. https: / / doi.org / 10.1063 / L2176850. Electroinductive waveguides have many similarities to magnetoinductive waveguides. In contrast to the magnetic coupling found in magnetoinductive waveguides, electroinductive waveguides are characterised by electric coupling between resonators that form the waveguide.

[0054] FIG. IB shows an example of an electroinductive resonator 102 that includes a conductive portion 106 and a non-conductive portion 108. The conductive portion 106 may be a conductive plate or film, such as metallic plate or film. The non-conductive portion 108 may be a hole, void, or slot in the conductive portion 106.

[0055] FIG. IC shows an example of an electroinductive waveguide 100 that includes resonators 102a, 102b, 102c, 102d, 102e.

[0056] The examples and embodiments described herein that include magnetoinductive waveguides could instead use electroinductive waveguides.

[0057] FIG. 2A to FIG. 2C show an example of a deformable object 200 that includes a waveguide 100 mounted on a support structure 204, according to an example. The waveguide 100 is formed of a series of elements 202 connected by connectors 210. The waveguide element 202 includes a resonator 102 mounted on substrate 206. The waveguide element 202 is mounted on a support structure 204 that is moveably linked to another structure, e.g., to another support structure 204, via at least one connector 210. In the example of FIG. 2A the resonator 102 is a metallic trace formed on a substrate 206. The waveguide element 202 is attached to the support structure 204, such that the substrate 206 moves with the support structure 204 (e.g., by being rigidly attached to the support structure 204).

[0058] FIG. 2B shows a series of waveguide elements 202 forming a waveguide 100, viewed from above (with respect to the waveguide element 202 of FIG. 2A). Arrow 208 shows, m FIG. 2B, the direction corresponding with the view of FIG. 2A. The waveguide elements 202 may move relative to each other by rotating about respective connectors 210, as shown in FIG. 2C.

[0059] The structure of the waveguide elements 202 is not particularly limited. For example support structures 204 and connectors 210 may be replaced with any structure. Where the waveguide 100 is to measure deformation of a deformable object 200, the resonators 102 may be associated with the deformable object 200 such that each resonator 102 moves with a respective portion of the deformable object 200. In some examples, a spacing between neighbouring resonators 102 is such that a magnetoinductive wave can be propagated along the waveguide 100 throughout the expected range of deformation of the deformable object 200.

[0060] FIG. 2A to FIG. 2C illustrate a loop of each resonator 102 oriented perpendicular to the extent of the waveguide 100. In contrast, the resonators 102 of FIG. 1A lie in the plane of the waveguide 100. Coupling between resonators 102 tends to be greater in the perpendicular arrangement of FIG. 2A to FIG. 2C, which generally leads to greater sensitivity to deformations. However, the parallel arrangement of FIG. 1A may be appropriate for some examples of a waveguide for deformation detection. For example, an arrangement of FIG. 1A may be easier or less expensive to produce, or may have a form factor that is more appropriate for some applications.

[0061] In some examples, the waveguide 100 may include three or more resonators 102.

[0062] Signals may be input to the waveguide 100 by a conductive connection to one of the resonators 102, or by an input resonator that is magnetoinductively coupled with one or more resonators 102 of the waveguide 100. Similarly, signals may be read from (or output by) the waveguide 100 via a conductive connection to one of the resonators 102, or by an output resonator that is magnetoinductively coupled with one or more of the resonators 102. Input and output may be performed by the same components. For example, a conductive input / output connection may be provided. Similarly, an input / output resonator may be magnetoinductively coupled with one or more of the resonators 102.

[0063] In some examples, a single input may be provided. In some examples a single output may be provided. In some examples, a single communication connection may provide both input and output.

[0064] An input signal input at an arbitrary location along the waveguide 100 may be propagated throughout the waveguide 100, and similarly, reflected signals, or other signals carried from any location along the waveguide 100 may be output at an arbitrary location along the waveguide 100. Accordingly, there is considerable design freedom in selecting locations along the waveguide 100 for an input, output, or both. Moreover, additional wiring or signal carrying components running along the waveguide 100 may be unnecessary. For example, an input and output may be situated at a proximal end of a deformable object 200, with the waveguide 100 extending between the proximal end and a distal end. Processing circuitry for receiving and processing a signal from the waveguide 100 may be provided at the proximal end of the deformable object 200. In this arrangement, additional wiring is not needed to carry signals to or from the resonator 102 at the distal end of the deformable object 200 (or other locations along the deformable object 200). Further, in this arrangement, all of the resonators 102 may receive an input signal from a single input, and signals carrying information about each resonator 102 may be obtained from a single output.

[0065] In some examples, the standing wave modes of the waveguide 100 may be determined by measuring signals reflected in the waveguide 100. For example, the impedance of the waveguide 100 at different frequencies may be measured. A signal input to the waveguide 100 may sweep through frequencies in a range of frequencies to obtain a spectrum of the impedance with varying frequency. An output signal obtained from waveguide 100 may be measured using a vector network analyser, for example.

[0066] In some examples, first and second resonators 102 of the plurality of resonators 102 are respectively associated with first and second portions of a robot, where the first and second portions are movable with respect to each other, such that relative movement of the first and second portions causes deformation of the magnetoinductive waveguide 100. For example, the first and second portions may be included in a part of a robot that is a soft robotics component of the robot, an articulated soft robotics component of the robot, a continuum soft robotics component of the robot, a rigid robotics component of the robot, a robotic limb driven by hydraulic or pneumatic actuators, or a compliant mechanism.

[0067] FIG. 2D illustrates a waveguide 100 having electroinductive resonators that are oriented perpendicular to the extent of the waveguide 100, similar to the magnetoinductive waveguide 100 of FIG. 2A, FIG. 2B, and FIG. 2C. The support structure 204 is not shown in FIG. 2D, and in some examples, the conductive portion 106 may form the support structure 204.

[0068] The waveguide 100 of FIG. 2D includes a stack of conductive plates with slots cut in them. The coupling between the plates is via electric fields, rather than magnetic fields, but otherwise the propagation effects and the behaviour of the electroinductive waveguide 100 of FIG. 2D is the same as the magnetoinductive waveguide 100 of FIG. 2A, FIG. 2B, and FIG. 2C.

[0069] FIG. 2D provides three views of the electroinductive waveguide 100. In (b) the waveguide 100 is straight (not bent). In (a) the waveguide 100 is bent in one direction, and in (c) it is bent in the opposite direction. The bent structures in (a) and (c) will experience different coupling from the straight structure. As the slots are offset from the axis of the bend, a bend in one direction will increase the coupling between the resonators 102, while the bend in the other direction will reduce the coupling between the resonators 102.

[0070] FIG. 3 illustrates a method 300 according to some examples. The method 300 may be implemented by a computer. In operation 302 data is received that is indicative of propagation of magnetoinductive waves in a magnetoinductive waveguide (or electroinductive waves in an electroinductive waveguide). The magnetoinductive waveguide includes a plurality of resonators 102 that are coupled so as to support magnetoinductive waves. In some examples, the waveguide 100 may include two or more resonators 102, and may include three or more resonators 102. The resonators 102 may be magnetoinductively coupled with each other.

[0071] In operation 304 information is determined, based on the received data, the information indicative of a configuration of the magnetoinductive waveguide 100. The configuration may correspond with a shape of the waveguide 100, or a relative orientation and / or position of a plurality of the resonators 102. The configuration may correspond with of a deformation, e.g., a deformation with respect to, or deviation from, a reference configuration.

[0072] In some examples time domain data, frequency domain data or both may be obtained from the received data. The time domain data, frequency domain data or both may be used in determining 304 the information indicative of a configuration of the magnetoinductive waveguide 100.

[0073] FIG. 4 shows an example plot 400 of frequency domain data that may be obtained from the waveguide 100 of FIG. 2A to FIG. 2C. FIG. 4 shows, on the vertical axis, the negative of impedance at an input to the magnetoinductive waveguide 100, with frequency on the horizontal axis. The impedance drops at five frequencies, corresponding with standing wave modes of the waveguide 100, and these frequencies correspond with the peaks 402a-402e in FIG. 4 (as the negative of the impedance is plotted). The frequencies of these peaks change in dependence on the relative positions and orientations of the resonators 102. Herein the term “pose” may be used to describe the position and orientation of an element.

[0074] FIG. 5 is a plot 500 illustrating the effect of bending the waveguide 100 on the input scattering parameter spectrum. FIG. 5 is a waterfall plot, with a series of plots arranged vertically. The impedance of each plot is shown on the vertical axis and the frequency is shown on the horizontal axis. The peaks of FIG. 4 appear as valleys in FIG. 5, as the impedance, rather than the negative impedance, is plotted. Each of the plots arranged along the vertical axis corresponds with a different time instance during a process of bending the waveguide 100 of FIG. 3 upwards (reducing the distance between the resonators 102) and then downwards (increasing the distance between the resonators 102). As such, the vertical position of the plot is indicative of the bend angle of the waveguide 100. As can be seen, the peaks 402a-402e move closer together as the distances between the resonators 102 are decreased, and move apart as the distances between the resonators 102 are increased.

[0075] As the waveguide 100 is bent the relative poses between the resonators 102 changes, leading to changes in the coupling between the resonators 102. The change in coupling leads to changes in the frequencies of the standing wave modes (i.e., the resonant frequencies, or resonances).

[0076] The frequency shifts are not symmetrical with the bend angle of the waveguide 100; the top to bottom symmetry in FIG. 5 is a result of bending the waveguide 100 up and down, such that it returning to its original configuration. The resonators 102 are not arranged symmetrically about the bend axis, and so deviations from the straight arrangement of the waveguide 100 in equal and opposite directions results in different resonant frequencies. As can be seen, the frequency shifts may be associated with a particular bend angle, such that a bend angle may be obtained from the frequency data. Similarly, the resonators 102 in the waveguide 100 illustrated in FIG. 2D are not symmetrical about the bend axis, such that the bends in (a) and (c) would result in different resonant frequencies in the waveguide 100.

[0077] The overall bend of the waveguide 100 is characterised by a bandwidth of the waveguide 100. The bandwidth corresponds with the distance between the outermost peaks 402a and 402e (i.e., the highest and lowest frequency peaks). More generally, the bandwidth may give an indication of the overall, or average, bend. In addition, other frequency shifts of the various peaks may provide more detailed information on the relative poses of the resonators 102. In some examples, peak heights may be used distinguish which element or elements are associated with a particular frequency shift.

[0078] Aggregate properties of the waveguide 100 change with configuration of the waveguide 100. Details of the propagation are varied by individual local changes between each pair of neighbouring resonators 102 (and possibly more distant resonators 102, such as next nearest neighbours, etc.). Where the local changes are uniform (e.g., the same bend angle is present between each pair of neighbouring resonators 102) the resonant frequencies may spread out evenly as the coupling changes are the same for each element. Differing local deformations of the waveguide 100 lead to defects in the waveguide 100 and result in uneven spreading of the resonant frequencies.

[0079] The frequency shifts, or other frequency data, may be analysed by comparing with calibrated data, or according to an empirical scheme, such as a best fit to frequency shifts associated with known configurations. Alternatively, the frequency data may be analysed by comparing or fitting to a model or simulation of the system. In other examples, machine learning could be used to analyse frequency shifts. For example, a neural network may be trained to determine a configuration of the waveguide 100 based on the frequency data. In some examples, a combination of deterministic calculations and neural algorithms may be used. The neural algorithms may be simple, low order neural algorithms, for example. Accordingly, in examples, low power microprocessors may be sufficient to analyse the signals obtained from the waveguide 100 to obtain the configuration of the waveguide 100. According to some examples, uses input admittances may be analised according to the principle of superposition.

[0080] Accordingly, determining 304 the deformation based on frequency-domain data may include determining frequencies corresponding with resonant frequencies, represented by peaks or troughs in the input scattering parameter spectrum.

[0081] If more resonators 102 are included in the waveguide 100, the number of resonant modes, and so the number of peaks, will increase. The frequencies of the outermost peaks are not dependent on the number of resonators 102, and so the bandwidth of the waveguide 100 is not dependent on the number of resonators 102.

[0082] FIG. 6A shows a simulated frequency dependence of impedance with bend angle in the arrangement of FIG. 2B, with resonant frequencies 402a to 402e shown. Here the bend angle is the angle between successive joints. As can be seen, the spacing of the peaks increases as the bend angle increases from 0° in one direction and the spacing of the peaks decreases as the bend angle increases from 0° in the opposite direction (shown as a negative angle).

[0083] FIG. 6B to FIG. 6D show an alternative arrangement for the waveguide 100, where the resonators 102 are positioned symmetrically with respect a bending axis. In FIG. 6A, the resonator 102 is positioned such that its centre lies on a line that is perpendicular to both the bend axis and the bending direction (assuming the waveguide 100 is bent to the left or right in FIG. 6A, with the bend axis perpendicular to the plane of the figure). Accordingly, a change in the relative pose of the resonators 102 due to a bend to the left will be equal and opposite to a bend of the same magnitude to the right. That is, the positions and orientations of the resonators 102 resulting from a bend to the right will be a mirror image of the bend to the left.

[0084] FIG. 6C shows another symmetrical arrangement of resonators 102, with the resonators 102 centred on the bend axis. Accordingly the relative poses of the resonators 102 would be equal and opposite for any equal and opposite pair of bends.

[0085] FIG. 6D shows a view the the arrangements of FIG. 6B and FIG. 6C from above, with the resonators 102 lying along the bend axis in this view.

[0086] FIG. 6E shows a simulated frequency dependence of impedance with bend angle in a symmetrical arrangement, such as in FIG. 6B, FIG. 6C, or FIG. 6D. As can be seen, bends of the same magnitude m opposite directions result in the same frequency shifts in the peaks 402a to 402e.

[0087] The asymmetric arrangement is able to distinguish the direction of the bend. The lowest bandwidth of the symmetrical arrangement, indicated by the smallest horizontal distance between the outermost peaks in FIG. 6E (which is at 0°) is larger than the lowest bandwidth in the asymmetric arrangement, which corresponds with the smallest horizontal distance between the outermost peaks in FIG. 6A (which is at -80°). With other factors being equal, an arrangement with resonators 102 arranged asymmetrically about a bend axis will typically experience grater changes in pose relative to other resonators 102 of the waveguides 100, when compared with resonators 102 arranged symmetrically about the bend axis. Accordingly, resonators 102 arranged asymmetrically about the bend axis may be more sensitive to bending about the bend axis.

[0088] In examples, the resonators 102 are rigid. The deformation of the waveguide 100 is determined on the basis of changes in relative pose (e.g., relative spacing and / or orientation) between the resonators 102 that cause a change in coupling between the resonators 102. The deformation of the waveguide 100 is not determined on the basis of changes in the structure or configuration of the individual resonators 102 themselves. For example, the determination is not based on, or does not rely on, stretching or compressing resonators 102 in order to change the coupling between the resonators 102 to determine the configuration of the waveguide 100.

[0089] Implementations are not limited to a waveguide 100 with a single, or well defined bend axis, and other, more complicated deformations of the waveguide 100 may be detected.

[0090] The shapes of the resonators 102 are not particularly limited. The examples in FIG. 1A and FIG. 2A to FIG. 2C show square resonators 102, but the resonators 102 could be circular, triangular, or any other shape, including irregular shapes and concave shapes. For example, crescent moon-shaped resonators 102 may be suitable for positioning at (e.g., on or in) a wall of a deformable object 200, such as the deformable object 200 shown in cross-section in FIG. 7 A. This arrangement may reduce obstruction or interference with other objects that are to be provided within deformable object 200.

[0091] The resonators 102 in FIG. 1A and FIG. 2A to FIG. 2C are illustrated as each having a single loop, but in some examples, each resonator 102 may include multiple loops, e.g., arranged in a spiral, as shown in FIG. 7B. This may permit a reduction in the area of the resonator 102 while maintaining the same or similar coupling, for example.

[0092] The resonators 102 may be 3D shapes or structures. For example, the resonators 102 may include conductively connected loops or partial loops on different faces of a substrate, or on different layers of a layered substrate (e.g., connected by metal vias through the substrate or substrate layers). This may permit a reduction in the area of the resonator 102 while maintaining the same or similar coupling, for example.

[0093] Time domain data may be obtained by providing an input pulse having multiple frequencies to the waveguide 100. The pulse will propagate along the waveguide 100 and the propagated or reflected signal may be measured. A reflected signal may be measured at the same point as the input, or at a different point. The measured signal will have an envelope, with different frequencies arriving at different times, indicative of dispersion within the waveguide 100. The time domain data may include information relating to a location along the waveguide 100, since the time of flight of the signal is indicative of a point along the waveguide 100 from which it was reflected. For example, a feature of the signal may be determined to be associated with particular resonator 102, based on the time between inputting the signal and receiving the reflected signal at the output, where the time indicates the distance travelled by the signal from the input to the particular resonator 102, and from that resonator 102 to the output.

[0094] In some cases, time domain data may be easier to obtain or analyse than frequency domain data. For example, time domain signalling may be easier to implement in electronics, and may use fewer computational resources to analyse. As with frequency domain data, time domain data may be analysed using various methods, such as calibration, comparison with empirical data, comparison or fitting to a model or simulation of the system, or methods based on machine learning.

[0095] Time domain data and frequency domain data may both be used to interrogate the standing wave modes of the waveguide 100, and may provide complimentary information.

[0096] In some examples, time domain data may be measured directly and a Fourier transform used to obtain frequency domain data. In some examples, frequency domain data may be measured directly and a Fourier transform used to obtain time domain data. In some examples, both frequency and time domain data may be measured directly.

[0097] Where time domain data is measured directly, an input signal to the waveguide 100 may include a pulse having a plurality of frequencies. The time of flight of the respective frequencies of the reflected pulse and / or the envelope of the reflected pulse may be analysed to obtain information on the configuration of the waveguide 100.

[0098] The input and output signals used for determining the configuration of the waveguide 100 may be referred to as configuration sensing signals. The waveguide 100 may act as a data channel, and carry signals in addition to the configuration sensing signals. For example, the waveguide 100 may carry data for communication between components that are communicatively coupled to the waveguide 100. Additionally, or alternatively, the waveguide 100 may carry power to one or more components, for example to power active electronics of those components.

[0099] FIG. 8 shows an example of a waveguide 100 having a plurality of resonators 102. A first resonator 102a is coupled with a first component 802, and a second resonator 102e is coupled with a second component 804. The first resonator 102a and second resonator 102e are shown located at ends of the waveguide 100, but could be any of the resonators 102 of waveguide 100. Similarly, the first component 802 and second component 804 are shown located at the ends of the waveguide 100, but could be located anywhere along the waveguide 100. The first component 802 and second component 804 are examples of components that are external to the waveguide 100. In some examples, the first component 802 and second component 804 may be positioned relatively close to the first resonator 102a and second resonator 102b, respectively.

[0100] The first component 802 is shown connected to the first resonator 102a by a first wire connection 806 and the second component 804 is shown connected to the second resonator 102 by a second wire connection 808. In other examples, magnetoinductive coupling could be used in place of one or both of the first wire connection 806 and second wire connection 808.

[0101] The first component 802 may be, for example, a power supply, and the second component 804 may be a component that is powered by the power supply, via waveguide 100. For example, if the deformable object 200 is a robotic limb, the second component 804 may be a light or a sensor, such as a video camera that receives power via the waveguide 100.

[0102] The second component 804 may receive data, such as control signals, from first component 802 via waveguide 100, and may provide data to the first component 802 via the waveguide 100. For example, where the first component 802 is a controller and second component 804 is a light or a sensor, such as a video camera, a control signal from first component 802 may instruct the second component 804 to turn on or off. For example, to switch the light on or off, or start or stop video recording. In addition, sensor data may be provided from the sensor to the first component 802 via the waveguide 100.

[0103] In some examples, both power and data may be carried between the first component 802 and the second component 804 via the waveguide 100. In some examples, power and data may be input separately at the same or different positions along the waveguide 100 by one or more first components 802.

[0104] As described above, the bandwidth of the waveguide 100 depends on the coupling between the resonators 102 and may decrease with changes in the configuration of the waveguide 100. In some examples, a bandwidth of a waveguide 100 that has resonators 102 arranged symmetrically around a bend axis (e.g., such that the bend axis passes though the loops of the resonators 102) may be less affected by bending of the waveguide 100. Similarly, coupling between resonators 102 located close to a bend axis may be less affected by deformations of the waveguide 100 than the coupling between resonators 102 located away from the bend axis. Accordingly, where the waveguide 100 is to carry signals in addition to the configuration sensing signals, improved performance with regard to those signals may be provided when the resonators 102 of the waveguide 100 are arranged close to, arranged symmetrically about, or arranged around the bend axis.

[0105] In some examples, a deformable object 200 may be provided with multiple waveguides 100. One or more of the waveguides 100 may be used for determining a configuration of the deformable object 200. In addition, one or more of the waveguides 100 may be used for carrying data, power, or both. Some waveguides 100 may perform more than one of carrying configuration sensing signals, carrying data and carrying power.

[0106] Where a waveguide 100 is to be used to carry configuration sensing signals and power, the power may be provided in a predetermined (e.g., narrow) frequency range. When frequencies are swept to generate the configuration sensing signals, the frequency sweep may step over (i.e., omit) the predetermined frequency range for carrying power. Alternatively, a filter (e.g., a notch filter) may be used to remove the predetermined frequency range from the signal to be analysed to obtain the configuration of the waveguide 100. In other examples, the power transfer may be temporarily suspended while measuring the configuration of the waveguide 100, and resumed following measurement of the configuration.

[0107] Accordingly, the received data may be filtered prior to determining information indicative of a deformation of the deformable object 200, to remove features of the data associated with at least one of power or data carried via the magnetoinductive waveguide 100, the power or data to be provided to or from a component external to the magnetoinductive waveguide 100.

[0108] In some examples, a frequency range associated with at least one of power or data carried via the magnetoinductive waveguide 100, is omitted from the data used to determine the configuration of the waveguide 100.

[0109] In some examples, the configuration of the waveguide 100 may be determined based on selected data indicative of propagation of magnetoinductive waves in the magnetoinductive waveguide 100, where the data is selected to correspond to a time window during which at least one of data or power transfer with components external to the magnetoinductive waveguide is suspended.

[0110] FIG. 9A shows an example of a waveguide 100 having each resonator 102 arranged symmetrically about a bend axis of the deformable object 200. The deformable object 200 may be a fibre, for example. This arrangement may be useful for sensing strain. Stretching or compression of the fibre along its axis (i.e., a change in the length of the fibre) will cause the spacing between the resonators 102 to vary, changing the coupling between the resonators 102 and leading to changes in the waves reflected from the waveguide 100.

[0111] FIG. 9B shows an example of a waveguide 100 having each resonator 102 arranged asymmetrically about a bend axis (e.g., off-centre with respect to the bend axis) of the deformable object 200, or fibre. This arrangement may be useful for detecting bending of the fibre along a particular axis. When the fibre is aligned along the z-axis and the resonators 102 are displaced from the bend axis along the y-axis, the waveguide 100 may be particularly sensitive to bending in the yz-plane.

[0112] FIG. 9C shows an example of a waveguide 100 having two sets of resonators 902 and 904. The resonator of the first set of resonators 902 and each resonator of the second set of resonators 904 is arranged asymmetrically about a bend axis (e.g., off-centre with respect to the bend axis) of the deformable object 200, or fibre, similarly to the arrangement of FIG. 9B. The first resonators 902 and second resonators 904 are displaced from the bend axis of the fibre in different directions. For example, the displacement of the second resonators 904 may be perpendicular to the displacement of the first resonators 902.

[0113] This arrangement may be useful for detecting bending of the fibre along various axes. When the fibre is aligned along the z-axis, the first resonators 902 are displaced from the bend axis along the y-axis, and the second resonators 904 are displaced from the bend axis along the x-axis, a component of bending in the yz-plane may be detected using the first resonators 902, and a component of bending in the xz-plane may be detected using the second resonators 904. The actual bend may be obtained from the composite of the bends measured in the yz- and yx-planes.

[0114] The set of first resonators 902 may be arranged to have a different set of resonant frequencies that the set of second resonators 904. For example, the first set of resonators 902 may be tuned to a frequency band that does not overlap the frequency band of the second set of resonators 904. In this case, they could be separately interrogated using a single output (e.g., a single pickup) in different frequency regimes. The resonant standing wave frequencies for the first resonators 902 may be tuned (for example) to a (relatively) low frequency, whilst the second resonators 904 may be tuned to a (relatively) high frequency. Accordingly, a single frequency sweep would provide monitoring of resonances in both sets of resonators.

[0115] In examples, the waveguide 100 may be used to sense objects that are proximate to the waveguide 100.

[0116] FIG. 10A shows an example of a waveguide 100 with a nearby object 1002. In this example, the nearby object 1002 is metallic. FIG. 10B shows the resonant frequencies 1004a to 1004e of the waveguide 100 in the absence of the nearby object 1002, and the resonant frequencies 1006a to 1006e when the nearby object 1002 is present. The frequency is plotted on the horizontal axis and the bend angle of the waveguide 100 is plotted on the vertical axis. Here, the bend angle is indicative of the average angle between successive resonators 102 of the waveguide 100. While the object 1002 was present, the waveguide 100 was moved from a configuration (at -20 on the vertical axis) in which it was bent toward the nearby object 1002, via a straight configuration (at 0 degrees), to a configuration with the waveguide 100 bent opposite the original bend (i.e., bent upwards in FIG. 10A). This generated the lines labelled 1006a-1006e. The object 1002 was then removed and the waveguide 100 and then bent back towards the original configuration to generate the lines labelled 1004a-1004e.

[0117] The resonance corresponding with line 1006c in the presence of object 1002 shows a notable “kink” or deviation 1008 from the corresponding linel004c in the absence of object 1002, due to the presence of the nearby object 1002. This deviation 1008 occurs at a bend angle of around 7°, when the waveguide 100 was closest to the nearby object 1002. Such deviations from the resonances in the absence of nearby objects may be used to determine the presence of, and possibly some properties of, nearby objects.

[0118] It is to be noted that some of the differences between the respective resonances with and without the nearby object 1002 are due to hysteresis in the movement of the support structure 204. For example, line 1006a is shifted to lower frequencies than line 1004a between -10° and-15°.

[0119] A conductor in the vicinity of the waveguide 100 may lead to an increase of one or more of the resonant frequencies. Ferrite materials may cause the one or more of the resonant frequencies to decrease. Material with dielectric loss, or weakly conducting material, may lead to a decrease in the Q-factor (quality factor) of a nearby resonator 102.

[0120] This may have application, for example, in robotics. The waveguide 100 may be used to determine a configuration of a robotic limb. Where the limb becomes stuck on an object, or meets resistance from an object in its environment, an expected configuration based on instructions to the actuators of the limb may differ from an actual configuration, as sensed by the waveguide 100. The ability to sense the object and possibly obtain information on its properties may provide useful information for a controller or operator to understand the cause of the deviation from the expected and actual configurations. Similarly, proximity sensing may assist with navigation, such as allowing a robot for operating within a pipe to sense the walls of the pipe.

[0121] In some examples, the configuration of the waveguide 100 may be determined from the resonant frequencies, for example by obtaining a best fit between the measured resonant frequencies and known calibration resonant frequencies associated with known configurations. Deviations from the measured resonant frequencies and the best-fit calibration resonant frequencies may then be analysed to obtain information on nearby objects 1002. The analysis may be based on a physical model or may use a suitably trained neural network, for example.

[0122] According to some examples, input admittances of the waveguide 100 may be analysed by applying the principle of superposition to obtain the configuration of the waveguide 100. To detect nearby objects, the admittance may then be monitored for deviations from the unperturbed case. Machine learning may be used to recognize signatures in the deviations, and using a trained neural network, determine the most probable configuration of the waveguide 100, and perturbations due to nearby objects.

[0123] According to examples, information relating to nearby objects 1002 is carried by the waveguide 100. The waveguide 100 acts as both a sensor and a data channel to provide the sensor data to an output of the waveguide 100, such that additional sensors and wiring are not needed to obtain and carry the proximity sensing information about nearby object 1002.

[0124] The configuration sensing signals may also be used to detect damage to the waveguide 100. If a resonator 102 is damaged, such that its resonant frequency changes, the waveguide 100 will have one fewer resonance. The effective removal of one of the resonators 102 (e.g., by damage to the resonator 102) results in 100% wave reflections from the defect that is created by the removal.

[0125] In some examples, the damaged resonator 102 or resonators 102 may be identified based on amplitudes of the impedance peaks, or with time of flight data, for example.

[0126] The waveguide 100 may act as both a sensor and a data channel to provide the sensor data to an output of the waveguide 100. As such, additional wires and sensing components are not needed along the length of the waveguide 100. A single interface may be used for input and output. In particular, a separate output and associated wiring is not needed for each damage sensor.

[0127] Resonators 102 of the waveguide 100 may be individually attached to a deformable object 200 to be monitored. For example, each resonator 102 may be directly attached to a different part of a robotic limb. In other examples, the resonators 102 may be coupled together by one or more support structures 204, for example, forming a fibre similar to those shown in FIG. 9A to FIG. 9C. This may form a standalone configuration sensor that can be used to detect its own bend angle. In some examples, the fibre (or similar element) may be the deformable object 200. In some examples, the fibre may be attached to a deformable object 200 to measure deformation of the deformable object 200.

[0128] In some examples, the resonators 102 may be disposed on, or in, a flexible substrate.

[0129] Examples described herein may be applied to any system the configuration of which is to be monitored or measured. The waveguide 100 may be provided on or in a robot limb to determine the configuration of the limb. In particular, accurately determining the configuration of so-called soft robots or compliant mechanisms has been challenging, particularly if motion of a limb is obstructed. However, examples described herein may provide a convenient and reliable approach to detecting the configuration of such robots and mechanisms. Accordingly, examples described herein provide a convenient structure for providing proprioception.

[0130] In an example, the deformable object 200, e.g., as shown in FIG. 2A to FIG. 2C has first and second portions that are moveable relative to each other. The waveguide 100 is to operate as a pose sensor, and resonators 102 of the waveguide 100 are arranged to be magnetoinductively coupled. A first resonator 102 of the waveguide 100 is arranged to move with the first portion of the deformable object 200, and a second resonator 102 of the waveguide 100 is arranged to move with the second portion of the deformable object 200. The deformable object 200 may be a robotic component, such as a complaint mechanism, a soft robotic limb, an articulated soft robotic limb, a continuum soft robotic limb, a rigid robotic limb, or a robotic limb driven by hydraulic or pneumatic actuators.

[0131] The robotic component may include an input component and a receiver component, the input component to supply at least one of power and data to the magnetoinductive waveguide, and the receiver component to receive the at least one of power and data via the magnetoinductive waveguide.

[0132] The robotic component may include, or be coupled with, processing circuitry arranged to receive data describing propagation of magnetoinductive waves in the magnetoinductive waveguide and to determine a pose of the robotic component based on the received data.

[0133] Examples described herein may be applied to human-machine interfaces. For example, a human-machine interface may include a glove to be worn on the hand of a user. A waveguide 100 may be provided on one or more of the fingers of the glove to detect bending of the finger. In examples a waveguide 100 may be provided on each of the fingers of the glove.

[0134] Waveguides 100 for sensing a configuration of an object may be included, for example, in cables or fabric membranes. For example, waveguides 100 may be included in clothing or boat sails.

[0135] According to examples herein, for configuration determination the system exploits the variable coupling between resonators 102 that are moving relative to one another. For example, as a multi-jointed bending limb moves, one or more resonators 102 attached to each unit form a waveguide 100 whose reflection characteristics are varied by the changes to their coupling.

[0136] According to examples herein, the waveguide 100 provides a confined wave propagation environment in which the effective wavelength may be very short. This is because the waveguide 100 is composed of an array of coupled circuits (resonators 102 or meta-atoms) each of which may be tuned to the same frequency, or to a particular spatial frequency pattern. Launching waves into the waveguide 100 may result in a complex interference pattern with a large number of unique spatial configurations. Careful choice of injection locations and the overall symmetry of the waveguide 100 results in being able to identify changes to that propagation environment, e.g., based on detection of reflected waves.

[0137] Examples may provide a single wire connection, with signals injected to and received from the waveguide 100 at a single point, with the received signals indicating a configuration of the waveguide 100.

[0138] According to examples, configuration of the waveguide 100 may be determined without requiring a complex distribution of sensors. The waveguide 100 may be structurally simple and may be straightforward to apply to or install in a deformable object 200 to be monitored.

[0139] Herein, the term configuration may be used to refer to the spatial shape or deformation of an object.

[0140] Certain methods and systems as described herein may be implemented by one or more processors that process program code that is retrieved from a storage medium, such as non-transitory storage medium. FIG. 11 shows an example of a device 1100 comprising a computer-readable storage medium 1102 (e.g. memory device) coupled to at least one processor 1104. The computer-readable medium 1102 may be any medium or media that can contain, store, or maintain programs and data for use by or in connection with an instruction execution system. Computer-readable medium 1102 can comprise any one of many physical media such as, for example, electronic, magnetic, optical, electromagnetic, or semiconductor media. More specific examples of suitable machine-readable media include, but are not limited to, a hard drive, a random-access memory (RAM), a read-only memory (ROM), an erasable programmable readonly memory, or a portable disc.

[0141] In FIG. 11, the computer-readable storage medium 1102 comprises program code 1106 to perform a method 300 corresponding to the embodiment shown in FIG. 3, that is: receiving data indicative of propagation of magnetoinductive waves in a magnetoinductive waveguide 100, the magnetoinductive waveguide 100 including a plurality of resonator elements; and determining, based on the received data, information indicative of a configuration of the magnetoinductive waveguide 100. The magnetoinductive waveguide 100 may be a waveguide 100, as described in any of the previous examples.

[0142] The device 1100 may be included in a deformable object 200, or may be communicatively coupled with waveguide 100 in a deformable object 200.

[0143] It will be appreciated that various changes and modifications can be made to the embodiments of the present invention without departing from the scope of the present application.

[0144] FIG. 12 shows a method 1200 of producing a configuration sensor for a robot. The configuration sensor may be a waveguide 100 according to any of the previously described examples. The method includes providing 1202 a first resonant element that is arranged to move with a first portion of the robot, the first resonant element 102 being a resonant element of a magnetoinductive, or electroinductive, waveguide of resonant elements. The method 1200 also includes providing a second resonant element 102 that is arranged to move with a second portion of the robot, the second resonant element being a resonant element of the waveguide of resonant elements. The magnetoinductive, or electroinductive, coupling between the first and second resonant elements is dependent on a relative pose of the first and second elements.

[0145] The first and second portions may be connected with each other via a moveable joint or a compliant structure, for example.

[0146] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0147] Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect or example are to be understood to be applicable to any other aspect or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. Examples are not restricted to the details of any foregoing examples. The Examples may extend to any novel one, or any novel combination, of the features disclosed in this specification, or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

What is claimed is:

1. A computer implemented method comprising:receiving data indicative of propagation of magnetoinductive or electroinductive waves in a magnetoinductive or electroinductive waveguide, the waveguide including a plurality of resonator elements; anddetermining, based on the received data, information indicative of a configuration of the waveguide.

2. The computer implemented method of claim 1, wherein at least one of:the determining includes obtaining, from the received data, time-domain data indicative of reflected magnetoinductive or electroinductive waves, and determining the deformation based, at least in part, on the time-domain data; andthe determining includes obtaining, from the received data, frequency-domain data indicative of a input scattering parameter spectrum of the magnetoinductive or electroinductive waves, and determining the deformation based, at least in part, on the frequency-domain data.

3. The computer implemented method of claim 2, wherein determining the deformation based on the frequency-domain data includes determining frequencies corresponding with peaks or troughs in the input scattering parameter spectrum.

4. The computer implemented method of claim 3, wherein determining the deformation includes determining one or more frequency shifts, relative to a input scattering parameter spectrum of a reference configuration, of the peaks or troughs in the input scattering parameter spectrum.

5. The computer implemented method of any one of claims 1 to 4, wherein the method further comprises at least one of:detecting an object proximate to the waveguide, based on the received data;detecting damage to the waveguide, based on the received data;filtering the received data, prior to determining the information indicative of the deformation, to remove features of the data associated with at least one of power or data carried via the waveguide to be provided to or from a component external to the waveguide;omitting, from data used in the determining, a frequency range associated with at least one of power or data carried via the waveguide to be provided to or from a component external to the waveguide; andselecting, for use in the determining, data indicative of propagation of magnetomductive or electroinductive waves in the waveguide that corresponds to a time window during which at least one of data or power transfer with components external to the waveguide is suspended.

6. The computer implemented method of any one of claims 1 to 5, wherein first and second resonator elements of the plurality of resonator elements are respectively associated with first and second portions of a robot, wherein the first and second portions are movable with respect to each other such that relative movement of the first and second portions causes deformation of the waveguide.

7. The computer implemented method of claim 6, wherein first and second portions are included in a part of the robot that is:a soft robotics component of the robot,an articulated soft robotics component of the robot,a continuum soft robotics component of the robot,a rigid robotics component of the robot,a robotic limb driven by hydraulic or pneumatic actuators, or a compliant mechanism.

8. Computer readable instructions that, when performed by a processing device, cause the processing device to carry out the computer implemented method of any one of claims 1 to 7.

9. A computer readable storage medium storing instructions that, when performed by a processing device, cause the processing device to carry out the computer implemented method of any one of claims 1 to 7.

10. A processing device arranged to determine a configuration of a deformable object, the device comprising:memory circuitry to store instructions; and processing circuitry to perform the instructions, wherein the instructions are to cause the processing circuitry to:receive data indicative of propagation of magnetoinductive or electroinductive waves in a magnetoinductive or electroinductive waveguide, the waveguide including a plurality of resonator elements, the plurality of resonator elements including at least first and second resonator elements, the first and second resonator elements are arranged to change their relative pose when the configuration of the deformable object is changed, wherein the relative pose describes at least one of (i) relative positions of the first and second resonator elements, and (ii) relative orientations of the first and second resonator elements; anddetermine, based on the received data, information indicative of the configuration of the deformable object.

11. A robotic component comprising:a first portion;a second portion, the second portion moveable relative to the first portion; anda pose sensor, the pose sensor comprising:a magnetoinductive or electroinductive waveguide comprising a plurality of magnetoinductively or electroinductively coupled resonant elements, the resonant elements including a first resonant element and a second resonant element, the first resonant element arranged to move with the first portion and the second resonant element arranged to move with the second portion.

12. The robotic component of claim 11, further comprising an input component and a receiver component, the input component to supply at least one of power and data to the waveguide, and the receiver component to receive the at least one of power and data via the waveguide.

13. The robotic component of claim 11 or 12, wherein the robotic component is selected from:a complaint mechanism,a soft robotic limb,a articulated soft robotic limb,a continuum soft robotic limb,a rigid robotic limb, ora robotic limb driven by hydraulic or pneumatic actuators.

14. The robotic component of any one of claims 11 to 13, further comprising processing circuitry arranged to receive data describing propagation of magnetoinductive orelectroinductive waves in the waveguide and to determine a pose of the robotic component based on the received data.

15. A method of producing a configuration sensor for a robot, the method comprising: providing, a first resonant element that is arranged to move with a first portion of the robot, the first resonant element being a resonant element of a magnetoinductive or electroinductive waveguide of resonant elements; andproviding a second resonant element that is arranged to move with a second portion of the robot, the second resonant element being a resonant element of the waveguide of resonant elements, whereinmagnetoinductive or electroinductive coupling between the first and second resonant elements is dependent on a relative pose of the first and second elements.

Images