Force-measuring pulley apparatus and method

Abstract

A force-measuring pulley apparatus100 to measure tension in an elongate flexible member 110 (e.g. belt, chain or rope) wherein the force measuring device, preferably a strain gauge or gauges 210, is p

Description

TECHNICAL FIELD The present disclosure relates to force-measuring pulley apparatus; for example, the present disclosure relates to a force-measuring pulley apparatus that is configured to measure a tension in a rope, belt or chain that passes over the forcemeasuring pulley apparatus. Moreover, the present disclosure relates to a method for using (namely, a method of using) the aforesaid force-measuring pulley apparatus to measure a tension in a rope, belt or chain that passes over the forcemeasuring pulley apparatus. Furthermore, the present disclosure also relates to a software product that is stored on a data carrier, wherein the software product is executable on computing hardware for implementing the aforesaid method. BACKGROUND Pulleys have been known for hundreds of years. An example known pulley is illustrated in FIG. 1, wherein the pulley is indicated generally by 10. The pulley 10 includes a wheel 20 having a round peripheral edge with two guiding sidewalls 30 that guide a rope, belt or chain 40 around at least a portion of the round peripheral edge. The wheel 20 is configured to be rotationally supported about a central pin or axle 50. Optionally, when in use, the wheel 20 rotates about the central pin or axle 50 when the central pin or axle 50 is fixed to be stationary; alternative, the pin or axle 50 is integral with the wheel 20, wherein the central pin or axle 50 rotates within a bearing support (not shown in FIG. 1). When it is desired to measure a tension developed in use in the rope, belt or chain 40, one option is to include a force-measurement sensor inline in the rope, belt or chain 40. However, such an approach may compromise a maximum load or safety of operation of the rope, belt or chain 40. Alternatively, a force acting on the pin or axle 50, or a bearing support for the pin or axle 50, may be measured by using a strain gauge arrangement, but results in a complicated mounting arrangement for the wheel 20. Thus, in many situations where pulleys are used, it is desired to measure an associated tension in the rope, belt or chain 40. Examples include the measurement of effort expended by a human being when performing a physical exercise on an exercise machine; alternatively, examples include measuring a weight of an item being lifted by a crane. As aforementioned, typically pulleys are carried by corresponding fixed pins or axles, wherein bearings are included to allow free rotation of the pulleys around their fixed pins or axles. As aforesaid, the tension in the rope, belt or chain 40 for a given pulley 10 may be sensed from a reaction force developed at its fixed pin or axle 50 and an angle through which its rope, belt or chain 40 is redirected. Correspondingly, a method for measuring a tension arising in a given rope, belt or chain 40 conventionally includes measuring a reaction force arising at the pin or axle 50. A load pin for a pulley wheel used in this way will normally have a larger diameter than a simple axle, as the load pin may beneficially be hollow to accommodate force measuring components and devices. Thus, such an implementation is not appropriate where it is desired to add measurement to an existing machine or system without also changing its pulley mounting arrangements. In a granted Chinese patent CN102507068B, "Internal cable tension measuring device for tension attenuation winch", there is described and claimed an internal cable tension measuring device for a tension attenuation winch; the internal cable tension measuring device includes a tension pulley, a big bearing, a force-exerting sleeve, a force sensor, a sensor seat, a flange and a flat key. Moreover, the internal cable tension measuring device is characterized in that as force is transversely exerted to the force sensor, the cable tension exerted on the tension pulley is exerted onto the force sensor arranged in the flange sleeve along the resultant force direction under the action of the force-exerting sleeve; suitable gaps are arranged between the flat key and the force-exerting sleeve as well as between the force-exerting sleeve and the flange sleeve. The sleeve is free from the influence of the weight of the device, wherein the precision of the stability of the tension measurement is ensured, and the device may thereby be suitable for coping with a variation of the cable wrap angle within a certain range. In a published United States patent US10107699B2, "Wireless enabled tension meter", a wireless-enabled tension meter is described. The wireless-enabled tension meter may include a pulley arrangement through which a portion of a guiding member is routed for use during a pull of conductor through a conduit network. In use, a tension force is exerted on the guiding member during the pull as the guiding member is pulled through the pulley arrangement. The wireless-enabled tension meter may also include a sensor for measuring the tension force, a wireless network interface, and a control module for performing operations. The operations performed by the control module may include capturing data corresponding to the tension force and causing the wireless network interface to send the data to a wireless communication device. A physical tether is used to provide electrical power to the sensor and its associated wireless network interface. SUMMARY The present disclosure seeks to address problems encountered with known pulley apparatus by providing an improved force-measuring pulley apparatus that is easier to install in existing systems and provides an enhanced accuracy of measurement; such an improved force-measuring pulley apparatus is defined in appended independent claim 1. Moreover, the present disclosure seeks to provide an enhanced method for using the improved force-measuring pulley apparatus; such an improved method is defined in appended independent claim 11. DESCRIPTION OF THE DIAGRAMS Embodiments of the present disclosure will be described with reference to the following drawings, wherein: FIG. 1 is an illustration of a known pulley wheel; FIG. 2 is an illustration of a force-measuring pulley apparatus of the present disclosure, wherein the apparatus includes a pulley wheel including an outer portion including a groove to guide and support a flexible elongate member (for example, a rope, a belt or a chain), an inner wheel that mates with a fixing bolt or mounting pin, and a bearing included between the pulley wheel and the inner wheel that allows free rotation of the pulley wheel relative to the inner wheel; FIG. 3 is an illustration of the pulley wheel of FIG. 2, wherein a tension in the flexible elongate member results in a reaction force F acting on the fixing bolt or mounting pin; the flexible elongate member passes over the pulley wheel and thereby is deflected by a deflection angle A; a tension in the flexible elongate member results in the reaction force F at the pulley wheel axis which is dependent on the tension in the flexible elongate member and the deflection angle A; FIG. 4 is an illustration of a practical implementation of the pulley wheel of the apparatus of FIG. 2; there is shown the outer portion comprising two parts that are joined by a force measurement plate arrangement; FIG. 5 is an exploded view of component parts of the force-measuring pulley apparatus of FIG. 2; FIG. 6A is an illustration of a practical implementation of the pulley wheel of the apparatus of FIG. 2, wherein a capacitive measurement arrangement is used for sensing strain arising in the pulley wheel and therefrom computing a force being applied to the pulley wheel; FIG. 6B is an illustration of the pulley wheel of FIG. 6A including the flexible elongate member engaging a peripheral region of the pulley wheel, wherein a position of the capacitive measurement arrangement is shown; and FIG. 7 is a flow chart depicting steps of a method for using the force-measuring pulley apparatus of FIGs. 2 to 6A, 6B. DESCRIPTION OF EXAMPLE EMBODIMENTS In overview, according to a first aspect, there is provided a force-measuring pulley apparatus for measuring a tension developed in an elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel, wherein the at least one pulley wheel is configured to be supported by a fixed support that bears the at least one pulley wheel at a substantially central region thereof, wherein a force-measuring device is included on the at least one pulley wheel that rotates when the force-measuring pulley apparatus is in operation, and wherein the force-measuring pulley apparatus includes a wireless communication arrangement for communicating wirelessly force measurement data representative of a force measured in use by the force-measuring device to a receiving data processing arrangement that is spatially remote from the portion of the at least one pulley wheel that rotates when the force-measuring pulley apparatus is in operation. The force-measuring pulley apparatus is of advantage in that the fixed support enables the apparatus to be retrofitted with minimal change, if any, to existing systems. Moreover, the inclusion of the force-measuring device in rotating parts of the apparatus is capable of improving an accuracy of tension measurement Beneficially, the force-measuring pulley apparatus may be used in a broad variety of mechanical systems utilizing various flexible elongate members to couple mechanical energy. Optionally, in the force-measuring pulley apparatus, the elongate flexible member includes at least one of: a rope, a belt, a chain. Beneficially, the force-measuring pulley apparatus may be retrofitted into a given system without a need to rewire the system to provide electrical power to operate the apparatus. Optionally, the force-measuring pulley apparatus further includes an energy-harvesting arrangement for generating electrical energy from rotation of the at least one pulley wheel relative to the fixed support that bears the at least one pulley wheel at a substantially central region thereof, wherein the energyharvesting arrangement is configured to provide the generated electrical energy to the force-measuring device for providing power for at least operating the wireless communication arrangement. More optionally, for the force-measuring pulley apparatus, the energy-harvesting arrangement includes an electromagnetic generator for converting a rotation motion of the at least one pulley wheel into the generated electrical energy, wherein the rotation motion is generated from rotation of the at least one pulley wheel by using a mechanical gear arrangement to drive the electromagnetic generator. Alternatively or additionally, more optionally, the energy-harvesting arrangement includes an electromagnetic generator for converting a rotation motion the at least one pulley wheel into the generated electrical energy, wherein the electromagnetic generator is implemented as a magnetically-coupled generator drive that is directly coupled to the at least one pulley wheel. Beneficially, in order for installation of the apparatus into the given system to be as easy and trouble-free as possible, the apparatus is configured to be selfcalibrating. Optionally, the force-measuring pulley apparatus includes a programmable calibration arrangement to account for one or more deflection angles of the elongate flexible member relative to the fixed support. Beneficially, the force-measuring pulley apparatus provides an enhanced accuracy of force measurement, namely tension measurement. Optionally, the forcemeasuring device includes a planar plate including strain sensors mounted thereon, wherein the strain sensors are configured to provide strain measurement in two substantially mutually orthogonal axes, wherein the plate is configured to experience strains generated from the tension developed in the elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel. More optionally, for the force-measuring pulley apparatus, the planar plate is configured for the strains resulting from the tension developed in the elongate flexible member to be linear strains, wherein the force-measuring pulley apparatus is configured to use linear scaling factors to infer orthogonal force components generated by the tension, wherein the inferred orthogonal force components are used in computing a magnitude of the tension. Yet more optionally, for the force-measuring pulley apparatus, the tension is computed as a vector sum of the two substantially orthogonal measurements of strain. Optionally, the strain sensors may be implemented using one or more resistive strain gauges, for example thin-film resistive strain gauges; for example, the strain gauges may be configured in a Wheatstone bridge arrangement. Alternatively, or additionally, the force measuring device may be implemented using one or more capacitive strain gauge sensors, as will be described in more detail below. Beneficially, the force-measuring device includes a configuration of capacitive displacement-sensing sensors whose capacitances vary as a function of changes in the tension developed in an elongate flexible member. Beneficially, the force-measuring pulley apparatus is configured for use in practical systems of industrial utility. Optionally, the force-measuring pulley apparatus is configuring for use in at least one of: (i) measuring a physical effort exerted by an athlete when using a cable strength training machine; (ii) measuring a weight of a load when being lifted by a cable crane; (iii) measuring a tension on a halliard of a sailing yacht; (iv) measuring a tension in a drive belt in an automotive engine; and (v) measuring a tension of a catenary wire in an electrified railway. According to a second aspect, there is provided a method for using a forcemeasuring pulley apparatus to measure a tension developed in an elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel, wherein the method includes: (i) configuring the at least one pulley wheel to be supported by a fixed support that bears the at least one pulley wheel at a substantially central region thereof; (ii) configuring a force-measuring device to be included on the at least one pulley wheel that rotates when the force-measuring pulley apparatus is in operation; and (iii) configuring the force-measuring pulley apparatus to include a wireless communication arrangement for communicating wirelessly force measurement data representative of a force measured in use by the forcemeasuring device to a receiving data processing arrangement that is spatially remote from the portion of the at least one pulley wheel that rotates when the force-measuring pulley apparatus is in operation. Optionally, the method includes arranging for the elongate flexible member to include at least one of: a rope, a belt, a chain. Optionally, the method further includes configuring the force-measuring pulley apparatus to further include an energy-harvesting arrangement for generating electrical energy from rotation of the at least one pulley wheel relative to the fixed support that bears the at least one pulley wheel at a substantially central region thereof, wherein the energy-harvesting arrangement is configured to provide the generated electrical energy to the force-measuring device for providing power for at least operating the wireless communication arrangement. More optionally, the method includes configuring the energy-harvesting arrangement to include an electromagnetic generator for converting a rotation motion of the at least one pulley wheel into the generated electrical energy, wherein the rotation motion is generated from rotation of the at least one pulley wheel by using a mechanical gear arrangement to drive the electromagnetic generator. Alternatively or additionally, the method includes configuring the energy-harvesting arrangement to include an electromagnetic generator for converting a rotation motion of the at least one pulley wheel into the generated electrical energy, wherein the energyharvesting arrangement includes an electromagnetic generator for converting a rotation motion the at least one pulley wheel into the generated electrical energy, wherein the electromagnetic generator is implemented as a magnetically-coupled generator drive that is directly coupled to the at least one pulley wheel. Optionally, the method includes configuring the force-measuring pulley apparatus to include a programmable calibration arrangement to account for one or more deflection angles of the elongate flexible member relative to the fixed support. Optionally, the method includes configuring the force-measuring device to include a substantially planar plate including strain sensors mounted thereon, wherein the strain sensors are configured to provide strain measurement in two substantially mutually orthogonal axes, wherein the plate is configured to experience strains generated from the tension developed in the elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel. More optionally, the method further includes configuring the planar plate for the strains resulting from the tension developed in the elongate flexible member to be linear strains, wherein the force-measuring pulley apparatus is configured to use linear scaling factors to infer orthogonal force components generated by the tension, wherein the inferred orthogonal force components are used in computing a magnitude of the tension. Yet more optionally, the method includes computing the tension as a vector sum of the two substantially orthogonal measurements of strain. Optionally, the strain sensors may be implemented using one or more resistive strain gauges, for example thin-film resistive strain gauges; for example, the strain gauges may be configured in a Wheatstone bridge arrangement. Alternatively, or additionally, the force measuring device may be implemented using one or more capacitive strain gauge sensors, as will be described in more detail below. Beneficially, the force-measuring device includes a configuration of capacitive displacement-sensing sensors whose capacitances vary as a function of changes in the tension developed in an elongate flexible member. Optionally, the method includes configuring the force-measuring pulley apparatus for at least one of: (i) measuring a physical effort exerted by an athlete when using a cable strength training machine; (ii) measuring a weight of a load when being lifted by a cable crane; (iii) measuring a tension on a halliard of a sailing yacht; (iv) measuring a tension in a drive belt in an automotive engine; and (v) measuring a tension of a catenary wire in an electrified railway. According to a third aspect, there is provided a software product stored on a machine-readable data storage medium, where the software product, when executed on a computing arrangement, is configured to implement a method of the second aspect using an apparatus of the first aspect. Referring next to FIG. 2, there is shown a schematic illustration of an example force-measuring pulley apparatus of the present disclosure; the force-measuring pulley apparatus is indicated generally by 100. The apparatus 100 is configured to receive a flexible elongate member 110, for example a belt, a chain or a rope; the flexible elongate member 110 is guided around at least part of a periphery of a pulley wheel 120; when the apparatus 100 is in operation, the pulley wheel 120 rotates as the flexible elongate member 110 moves. The pulley wheel 120 is a rotatable component that is supported by bearings onto an inner wheel 130, wherein the inner wheel 130 is beneficially fixed and does not rotate when the apparatus 100 is in operation. The inner wheel 130 is secured onto a support arrangement (not shown) by way of a bolt or pin 140. The apparatus 100 further includes an energy harvesting arrangement 200 that is configured to generate electrical energy from rotation of the pulley wheel 120 relative to the inner wheel 130, when the apparatus 100 is in use. The energy harvesting arrangement 200 is beneficially implemented as an electromagnetic generator, for example as a form of alternator or dynamo. The energy harvesting arrangement 200 is beneficially mounted substantially on the pulley wheel 120. Moreover, the apparatus 100 beneficially further comprises a sensor arrangement 210, for example implemented using one or more strain gauges mounted to a plate; strain experienced by the plate when in use is beneficially a function of a force F developed by the flexible elongate member 110 onto the pulley wheel 120, wherein the force F is a function of elongate tension occurring along the flexible elongate member 110. Furthermore, the apparatus 100 further comprises a first data processor 220 for processing a sensing signal received from the sensor arrangement 210 to generate corresponding output data. Additionally, the apparatus 100 further comprises a wireless transmitter 230 for receiving the output data and transmitting the output data to a wireless receiver 300 disposed remotely in respect of the pulley wheel 120. The wireless receiver 300 is configured to wirelessly receive the output data. Yet additionally, the wireless receiver 300 is coupled to a second data processor 310, wherein the second data processor 310 is configured to process the output data to generate measurement data indicative of a tension measurement that is representative of the tension arising in the flexible elongate member 110. The energy harvesting arrangement 200, the sensor arrangement 210, the first data processor 220 and the wireless transmitter 230 rotate as the pulley 120 rotates, whereas the wireless receiver 300 and the second data processor 310 remain stationary. Additionally, the energy harvesting arrangement 200 is configured to provide operating power to the sensor arrangement 210, the first data processor 220 and the wireless transmitter 230. Optionally, the energy harvesting arrangement 200 includes an energy storage device (not shown), for example a rechargeable battery, an ultracapacitor, a supercapacitor or similar, that enables wireless communication from the pulley wheel 120 to the wireless receiver 300, even when the pulley wheel 120 is stationary relative to the inner wheel 130. It will be appreciated that components 200 to 310 are shown schematically by blocks in FIG. 2, and that various practical implementations may be utilized in practice. The wireless transmitter 230 and the wireless receiver 300 may be configured to function with BlueTooth® communication protocol, although other communication protocols may be utilized within the scope of the present disclosure. Referring next to FIG. 3, the flexible elongate member 110 is engaged with the pulley wheel 120 over an angle A, wherein a force F acts on the bolt or pin 140. Referring next to FIGs. 4 and 5, there is shown a practical implementation of the force-measuring pulley apparatus 100, wherein component parts of the pulley when 120 are denoted by 120A, 120B, 120C and component parts of the inner wheel 130 have various bearings associated therewith. The components parts may be optionally secured together by screws or similar fasteners, to enable disassembly of the apparatus 100, for example for maintenance or repair purposes. In FIG. 5, there is shown an exploded view of component parts of the apparatus 100. Many component parts of the apparatus 100 are annular ring-like components that concentrically fit together to construct the apparatus 100. Optional features of the apparatus 100 will next be described. The apparatus 100 includes one or more bearings between the rotatable pulley wheel 120 and the fixed inner wheel 130, wherein the fixed inner wheel 130 mates with the fixed pin or bolt 140. The bearings serve to reduce, for example to minimise, friction between the rotating pulley wheel 120 and the fixed inner wheel 130. The pulley wheel 120 includes one or more force indicating devices, for example the sensor arrangement 210, to measure forces applied to the pulley wheel 120 with respect to the fixed inner wheel 130. Beneficially, optionally, the one or more force indicating devices are located in the pulley wheel 120 as this allows the use of smaller and lower cost bearings than would be required if the one or more force indicating devices were located in the fixed inner wheel 130. The one or more force indicating devices are coupled to wireless data transmission means, for example implemented using the wireless transmitter 230 and the corresponding wireless receiver 300, which relays measurements of force from the pulley wheel 120 of the pulley apparatus 100 to the wireless receiver 300 and its associated second data processor 310. Operating electrical power for the wireless transmitter 230 and optionally the wireless receiver 300 for the sensor arrangement 210 may be harvested from the rotation of the pulley wheel 120. The power harvesting may use an electromagnetic device such as a dynamo or solenoid. The electrical power harvesting device is ideally mounted on the rotating part of the pulley apparatus 100, namely onto the pulley wheel 120. A dynamo used for power harvesting is ideally driven by a gear coupled to the inner wheel 130 of the apparatus 100. The dynamo may be driven by a mechanism that results in a pulsed motion. Examples of the gear include a Geneva drive, or a magnetically coupled gear. These types of gear have the advantage of increasing the maximum rotation speed of the dynamo and hence its output potential for a given rotation speed of the pulley wheel 120. This maximum rotation speed for use in the gear is important in applications where the rotation of the pulley wheel 120 is relatively slow (for example, less than 500 RPM). The pulley wheel 120 may have a groove or slot around its peripheral edge to help guide the flexible elongate member 110, or may be barrelled to guide the flexible elongate member 110. The pulley apparatus 100 may include a data storage arrangement, for example a flash data memory, for storing a calibration constant which may be used to calculate the tension in the flexible elongate member 110 from the measured reaction force by making a correction for the deflection angle A. The sensor arrangement 210 may be configured to include a plate; wherein strain sensors are optionally arranged onto the plate, to provide strain measurements in two substantially mutually orthogonal axes; however, it will be appreciated that alternative types of sensors may be used as an alternative or in addition to strain gauges; for example, capacitive strain sensors may be used. The plate is beneficially scaled so that applied shear forces result in linear strains and thus measurement of the strains may be used to infer the orthogonal force components with simple linear scaling factors. The reaction force F is calculated as the magnitude of the vector sum of the two substantially orthogonal measurements. The pulley apparatus 100 may include a means of storing the linear scaling factors for the two orthogonal measurement axes, for example a non-volatile flash data memory. Alternatively, as aforementioned, the sensor arrangement 210 may measure the distortion of the pulley wheel 120 under load through any applicable displacement measurement means including interdigitated electrode capacitive displacement sensing, magnetic inductive displacement sensing, piezoelectric strain sensing and others. Referring next to FIGs. 6A, 6B, an alternative implementation of the aforesaid pulley wheel 100 is indicated generally by 400 in FIG. 6A in exploded view, in FIG. 6B indicated generally by 450 with its associated flexible elongate member 110. In overview, when in operation, projecting members 420 support an annular rigid circuit board 410; The annular rigid circuit board 410 may be manufactured from fibreglass, a ceramic material or similar. Capacitive plates on the annular rigid circuit board 410 form corresponding capacitors with an inside edge or spokes of the pulley wheel 120A. Forces acting on the pulley wheel 120A cause strain movement (namely deformation) of the pulley wheel 120A that causes capacitances of the capacitors to vary that is detected by electronic components included on the annular rigid circuit board 410. For example, the capacitors may be configured in a differential a.c.-excited Wheatstone bridge arrangement, although other configuration are feasible within the scope of the present disclosure as described below. Beneficially, the pulley wheel 400 uses the annular rigid circuit board 410 that is rigidly mounted to a central boss of an aluminium pulley body. On the rim of the circuit board 410, there are included a plurality of electrodes that capacitively couple with a flat rim on the body; for example, in practical embodiments of the pulley wheel 400, there are four flats or spokes of the pulley wheel 120A that may be used, although such a scheme would work just as well with a continuous inwardly-facing inside rim of the pulley wheel 120A. The central mounting of the annular rigid circuit board 410 is displaced from the inwardly-facing flat rim of the pulley wheel 120A to give a well controlled gap, for example a 0.1 mm gap, for example a gap in a range of 0.05 mm to 0.25 mm, between the electrodes and the inwardly-facing rim. Around the inner edge of the annular rigid circuit board 410 is an exposed conductor that makes a ground connection to the Aluminium body of the pulley wheel 400. Beneficially, the pulley wheel 120A is asymmetric in use, so that the effect of loading the pulley wheel 120A is to cause it to deform with a displacement of the inwardly-facing inside rim towards, alternatively away, from the annular rigid circuit board 410. Such spatial displacements result in a large change in the capacitances of the electrodes to the ground circuit including the Aluminium body. Electronic components of the annular rigid circuit board 410 measure these capacitances to provide a 2-axis measurement of the distortion of the pulley wheel 120A, wherein the distortion varies as load or force on the pulley wheel 120A is varied. When the pulley wheel 400 is in operation, there typically occurs a displacement, namely a change in the aforesaid gap between the electrodes and the inwardly-facing inside rim of the pulley wheel 120A in the region of tens of micrometres; as aforementioned, the gap is nominally 100 micrometres. Such gaps in combination with an exposed area of the electrodes facing the inwardly-facing inside rim results in the capacitors having a capacitance in a region of tens of picoFarads (pF). In a practical implementation of the pulley wheel 400, it is important that the annular rigid circuit board 410 is flat and that there are no significant mechanical loads on it; it will be appreciated that the annular rigid circuit board 410 is considerably less stiff than the pulley wheel 120A. The annular rigid circuit board 410 is held in place in the centre by a clamping ring which ensures a good electrical connection to an Aluminium body of the pulley wheel 400. Beneficially, the energy harvesting arrangement 200 is cantilevered off this ring and is careful designed to not touch the annular rigid circuit board 410. In an example implementation of the pulley wheel 400, when in operation, the capacitive measurements are made in the pulley wheel 400 by observing the time taken to discharge a pre-charged electrode with a fixed microamp current source. One electrode is measured at a given time with other electrodes concurrently being grounded. A complete measurement cycle may be completed in tens of microseconds, thereby enabling the pulley wheel 400 to being extremely power efficient when in use. Referring next to FIG. 7, it will be appreciated that the first data processor 220 and the second data processor 310 are configured to execute one or more software products for implementing a method for operating the pulley apparatus 100. The method includes steps 1010 to 1040 indicated generally by 1000 in FIG. 7. The method 1000 relates to using the force-measuring pulley apparatus 100 to measure a tension developed in the elongate flexible member 110 that is supported in use on at least a portion of a peripheral region of at least one pulley wheel 120. In a first step 1010 of the method 1000, the method 1000 includes configuring the at least one pulley wheel 120 to be supported by a fixed support that bears the at least one pulley wheel 120 at a substantially central region thereof; for example, the fixed support includes the inner wheel 130 and its associated pin or bolt 140. In a second step 1020, the method 1000 includes configuring a force-measuring device, for example the sensor arrangement 210, to be included on the at least one pulley wheel 120 that rotates when the force-measuring pulley apparatus 100 is in operation. In a third step 1030, the method 1000 includes configuring the force-measuring pulley apparatus 100 to include a wireless communication arrangement, for example implemented using the first data processor 220 and its associated wireless transmitter 230, for communicating wirelessly force measurement data representative of a force measured in use by the force-measuring device, for example the sensor arrangement 210, to a receiving data processing arrangement, for example implemented using the wireless receiver 300 and its associated second data processor 230, that is spatially remote from the portion of the at least one pulley wheel 120 that rotates when the force-measuring pulley apparatus 100 is in operation. In an optional fourth step 1040, the method 1000 includes arranging for the force-measuring device, for example the sensor arrangement 210, to include a planar plate including strain sensors mounted thereon, wherein the strain sensors are configured to provide strain measurement in two substantially mutually orthogonal axes, wherein the plate is configured to experience strains generated from the tension developed in the elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel. More optionally, the fourth step 1040 includes configuring the planar plate for the strains resulting from the tension developed in the elongate flexible member 110 to be linear strains, wherein the force-measuring pulley apparatus 100 is configured to use linear scaling factors to infer orthogonal force components generated by the tension, wherein the inferred orthogonal force components are used in computing a magnitude of the tension. Yet more optionally, in the step 1040, the tension is computed as a vector sum of the two substantially orthogonal measurements of strain. It will be appreciated from the foregoing that the force-measuring pulley apparatus 100 is very compact, robust and convenient to use. The apparatus 100 is reconfigurable on account of being implemented using one or more software products that are executed on the first data processor 220 and the second data processor 310. The apparatus 100 may be incorporated as a component part of new designs of systems, alternatively retrofitted to existing systems for upgrading purposes. For example, the method 1000 further includes configuring the force-measuring pulley apparatus 100 for at least one of: (i) measuring a physical effort exerted by an athlete when using a cable strength training machine; (ii) measuring a weight of a load when being lifted by a cable crane; (iii) measuring a tension on a halliard of a sailing yacht; (iv) measuring a tension in a drive belt in an automotive engine; and (v) measuring a tension of a catenary wire in an electrified railway. However, other uses for the force-measuring pulley apparatus 100 are feasible, in addition to use examples provided in the foregoing description.

Claims

1. A force-measuring pulley apparatus for measuring a tension developed in an elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel,wherein the at least one pulley wheel is configured to be supported by a fixed support that bears the at least one pulley wheel at a substantially central region thereof,wherein a force-measuring device is included on the at least one pulley wheel that rotates when the force-measuring pulley apparatus is in operation, andwherein the force-measuring pulley apparatus includes a wireless communication arrangement for communicating wirelessly force measurement data representative of a force measured in use by the force-measuring device to a receiving data processing arrangement that is spatially remote from the portion of the at least one pulley wheel that rotates when the force-measuring pulley apparatus is in operation.

2. A force-measuring pulley apparatus of claim 1, wherein the elongate flexible member includes at least one of: a rope, a belt, a chain.

3. A force-measuring pulley apparatus of claim 1 or 2, wherein the forcemeasuring pulley apparatus further includes an energy-harvesting arrangement for generating electrical energy from rotation of the at least one pulley wheel relative to the fixed support that bears the at least one pulley wheel at a substantially central region thereof, wherein the energy-harvesting arrangement is configured to provide the generated electrical energy to the force-measuring device for providing power for at least operating the wireless communication arrangement.

4. A force-measuring pulley apparatus of claim 3, wherein the energyharvesting arrangement includes an electromagnetic generator for converting a rotation motion of the at least one pulley wheel into the generated electrical energy, wherein the rotation motion is generated from rotation of the at least one pulley wheel by using a mechanical gear arrangement to drive the electromagnetic generator.

5. A force-measuring pulley apparatus of claim 3 or 4, wherein the energyharvesting arrangement includes an electromagnetic generator for converting a rotation motion the at least one pulley wheel into the generated electrical energy, wherein the electromagnetic generator is implemented as a magnetically-coupled generator drive that is directly coupled to the at least one pulley wheel.

6. A force-measuring pulley apparatus of any one of the preceding claims, wherein the force-measuring pulley apparatus includes a programmable calibration arrangement to account for one or more deflection angles of the elongate flexible member relative to the fixed support.

7. A force-measuring pulley apparatus of any one of the preceding claims, wherein the force-measuring device includes a planar plate including strain sensors mounted thereon, wherein the strain sensors are configured to provide strain measurement in two substantially mutually orthogonal axes, wherein the plate is configured to experience strains generated from the tension developed in the elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel.

8. A force-measuring pulley apparatus of claim 7, wherein the planar plate is configured for the strains resulting from the tension developed in the elongate flexible member to be linear strains, wherein the force-measuring pulley apparatus is configured to use linear scaling factors to infer orthogonal force components generated by the tension, wherein the inferred orthogonal force components are used in computing a magnitude of the tension.

9. A force-measuring pulley apparatus of claim 8, wherein the tension is computed as a vector sum of the two substantially orthogonal measurements of strain.

10. A force-measuring pulley apparatus of any one of the preceding claims, wherein the force-measuring device includes a configuration of capacitive displacement-sensing sensors whose capacitances vary as a function of changes in the tension developed in an elongate flexible member.

11. A force-measuring pulley apparatus of any one of the preceding claims, wherein the force-measuring pulley apparatus is configuring for use in at least one of:(i) measuring a physical effort exerted by an athlete when using a cable strength training machine;(ii) measuring a weight of a load when being lifted by a cable crane;(iii) measuring a tension on a halliard of a sailing yacht;(iv) measuring a tension in a drive belt in an automotive engine; and (v) measuring a tension of a catenary wire in an electrified railway.

12. A method for using a force-measuring pulley apparatus to measure a tension developed in an elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel, wherein the method includes:(i) configuring the at least one pulley wheel to be supported by a fixed support that bears the at least one pulley wheel at a substantially central region thereof;(ii) configuring a force-measuring device to be included on the at least one pulley wheel that rotates when the force-measuring pulley apparatus is in operation; and(iii) configuring the force-measuring pulley apparatus to include a wireless communication arrangement for communicating wirelessly force measurement data representative of a force measured in use by the forcemeasuring device to a receiving data processing arrangement that isspatially remote from the portion of the at least one pulley wheel that rotates when the force-measuring pulley apparatus is in operation.

13. A method of claim 12, wherein the method includes arranging for the elongate flexible member to include at least one of: a rope, a belt, a chain.

14. A method of claim 12 or 13, wherein the method further includes configuring the force-measuring pulley apparatus to further include an energyharvesting arrangement for generating electrical energy from rotation of the at least one pulley wheel relative to the fixed support that bears the at least one pulley wheel at a substantially central region thereof, wherein the energyharvesting arrangement is configured to provide the generated electrical energy to the force-measuring device for providing power for at least operating the wireless communication arrangement.

15. A method of claim 14, wherein the method includes configuring the energyharvesting arrangement to include an electromagnetic generator for converting a rotation motion of the at least one pulley wheel into the generated electrical energy, wherein the rotation motion is generated from rotation of the at least one pulley wheel by using a mechanical gear arrangement to drive the electromagnetic generator.

16. A method of claim 14 or 15, wherein the method includes configuring the energy-harvesting arrangement to include an electromagnetic generator for converting a rotation motion of the at least one pulley wheel into the generated electrical energy, wherein the electromagnetic generator is implemented as a magnetically-coupled generator drive that is directly coupled to the at least one pulley wheel.

17. A method of any one of claims 12 to 16, wherein the method includes configuring the force-measuring pulley apparatus to include a programmable calibration arrangement to account for one or more deflection angles of the elongate flexible member relative to the fixed support.

18. A method of any one claims 12 to 17, wherein the method includes configuring the force-measuring device to include a planar plate including strain sensors mounted thereon, wherein the strain sensors are configured to provide strain measurement in two substantially mutually orthogonal axes, wherein the plate is configured to experience strains generated from the tension developed in the elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel.

19. A method of claim 18, wherein the method further includes configuring the planar plate for the strains resulting from the tension developed in the elongate flexible member to be linear strains, wherein the force-measuring pulley apparatus is configured to use linear scaling factors to infer orthogonal force components generated by the tension, wherein the inferred orthogonal force components are used in computing a magnitude of the tension.

20. A method of claim 19, wherein the method includes computing the tension as a vector sum of the two substantially orthogonal measurements of strain.

21. A method of claim 19, wherein the method includes configuring the forcemeasuring device to include a configuration of capacitive displacement-sensing sensors whose capacitances vary as a function of changes in the tension developed in an elongate flexible member.

22. A method of any one of claims 12 to 21, wherein the method includes configuring the force-measuring pulley apparatus for at least one of:(i) measuring a physical effort exerted by an athlete when using a cable strength training machine;(ii) measuring a weight of a load when being lifted by a cable crane;(iii) measuring a tension on a halliard of a sailing yacht;(iv) measuring a tension in a drive belt in an automotive engine; and (v) measuring a tension of a catenary wire in an electrified railway.

23. A software product stored on a machine-readable data storage medium, where the software product, when executed on a computing arrangement, is configured to implement a method of any one of claims 12 to 22.THE AMENDMENTS TO THE CLAIMS ARE AS FOLLOWS:23APPLICANT'S AMENDED CLAIM SET(Clean copy version)CLAIMS1. A force-measuring pulley apparatus for measuring a tension developed in an elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel, the force-measuring pulley apparatus comprises:the at least one pulley wheel;a force-measuring device;a wireless communication arrangement; andan energy-harvesting arrangement,wherein the at least one pulley wheel includes an outer portion configured to guide and support the elongate flexible member, and an inner wheel that mates with a fixing bolt or mounting pin, and a bearing included between the at least one pulley wheel and the inner wheel that allows free rotation of the at least one pulley wheel relative to the inner wheel,wherein the at least one pulley wheel is configured to be supported by a fixed support that bears the at least one pulley wheel at a substantially central region thereof,wherein the force-measuring device is included on the at least one pulley wheel that rotates when the force-measuring pulley apparatus is in operation, wherein the force-measuring device is configured to measure distortion of the at least one pulley wheel under load to determine the tension developed in the elongate flexible member, and wherein the force-measuring device includes a configuration of capacitive displacement-sensing sensors whose capacitances vary as a function of changes in the tension developed in the elongate flexible member,wherein the wireless communication arrangement is configured to communicate wirelessly force measurement data representative of a force measured in use by the force-measuring device to a receiving data processing arrangement that is spatially remote from the portion of the at least one pulley wheel that rotates when the forcemeasuring pulley apparatus is in operation,wherein the energy-harvesting arrangement is configured to generate electrical energy from rotation of the at least one pulley wheel relative to the fixed support that bears the at least one pulley wheel at a substantially central region thereof, and wherein the energy-harvesting arrangement is configured to provide the generated electrical energy to the force-measuring device for providing power for at least operating the wireless communication arrangement.

2. The force-measuring pulley apparatus of claim 1, wherein the elongate flexible member includes at least one of: a rope, a belt, a chain.

3. The force-measuring pulley apparatus of claim 1, wherein the energy-harvesting arrangement includes an electromagnetic generator for converting a rotation motion of the at least one pulley wheel into the generated electrical energy, wherein the rotation motion is generated from rotation of the at least one pulley wheel by using a mechanical gear arrangement to drive the electromagnetic generator.

4. The force-measuring pulley apparatus of claim 1 or 3, wherein the energyharvesting arrangement includes an electromagnetic generator for converting a rotation motion the at least one pulley wheel into the generated electrical energy, wherein the electromagnetic generator is implemented as a magnetically-coupled generator drive that is directly coupled to the at least one pulley wheel.

5. The force-measuring pulley apparatus of any one of the preceding claims, wherein the force-measuring pulley apparatus includes a programmable calibration arrangement to account for one or more deflection angles of the elongate flexible member relative to the fixed support.

6. The force-measuring pulley apparatus of any one of the preceding claims, wherein the force-measuring device includes a planar plate including strain sensors mounted thereon, wherein the strain sensors are configured to provide strain measurement in two substantially mutually orthogonal axes, wherein the plate is configured to experience strains generated from the tension developed in the elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel.

7. The force-measuring pulley apparatus of claim 6, wherein the planar plate is configured for the strains resulting from the tension developed in the elongate flexible member to be linear strains, wherein the force-measuring pulley apparatus is configured to use linear scaling factors to infer orthogonal force components generated by the tension, wherein the inferred orthogonal force components are used in computing a magnitude of the tension.

8. The force-measuring pulley apparatus of claim 7, wherein the tension is computed as a vector sum of the two substantially orthogonal measurements of strain.

9. The force-measuring pulley apparatus of any one of the preceding claims, wherein the force-measuring pulley apparatus is configuring for use in at least one of:(i) measuring a physical effort exerted by an athlete when using a cable strength training machine;(ii) measuring a weight of a load when being lifted by a cable crane;(iii) measuring a tension on a halliard of a sailing yacht;(iv) measuring a tension in a drive belt in an automotive engine; and(v) measuring a tension of a catenary wire in an electrified railway.

10. A method for using a force-measuring pulley apparatus to measure a tension developed in an elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel, wherein the forcemeasuring pulley apparatus comprises the at least one pulley wheel, a force measuring device, a wireless communication arrangement and an energyharvesting arrangement, wherein the method includes:(i) configuring an outer portion of the at least one pulley wheel to guide and support the elongate flexible member, and an inner wheel that mates with a fixing bolt or mounting pin, and a bearing included between the at least one pulley wheel and the inner wheel that allows free rotation of the at least one pulley wheel relative to the inner wheel;(ii) configuring the at least one pulley wheel to be supported by a fixed support that bears the at least one pulley wheel at a substantially central region thereof;(iii) configuring the force-measuring device to be included on the at least one pulley wheel that rotates when the force-measuring pulley apparatus is in operation, wherein the force-measuring device is configured to measure distortion of the at least one pulley wheel under load to determine the tension developed in the elongate flexible member, and wherein the force-measuring device includes a configuration of capacitive displacement-sensing sensors whose capacitances vary as a function of changes in the tension developed in the elongate flexible member;(iv) configuring the force-measuring pulley apparatus to include the wireless communication arrangement for communicating wirelessly force measurement data representative of a force measured in use by the force measuring device to a receiving data processing arrangement that is spatially remote from the portion of the at least one pulley wheel that rotates when the force-measuring pulley apparatus is in operation; and(v) configuring the force-measuring pulley apparatus to include the energyharvesting arrangement for generating electrical energy from rotation of the at least one pulley wheel relative to the fixed support that bears the at least one pulley wheel at a substantially central region thereof, wherein the energy-harvesting arrangement is configured to provide the generated electrical energy to the forcemeasuring device for providing power for at least operating the wireless communication arrangement.

11. The method of claim 10, wherein the method includes arranging for the elongate flexible member to include at least one of: a rope, a belt, a chain.

12. The method of claim 10, wherein the method includes configuring the energyharvesting arrangement to include an electromagnetic generator for converting a rotation motion of the at least one pulley wheel into the generated electrical energy, wherein the rotation motion is generated from rotation of the at least one pulley wheel by using a mechanical gear arrangement to drive the electromagnetic generator.

13. The method of claim 10 or 12, wherein the method includes configuring the energy-harvesting arrangement to include an electromagnetic generator for converting a rotation motion of the at least one pulley wheel into the generated electrical energy, wherein the electromagnetic generator is implemented as a magnetically-coupled generator drive that is directly coupled to the at least one pulley wheel.

14. The method of any one of claims 10 to 13, wherein the method includes configuring the force-measuring pulley apparatus to include a programmable calibration arrangement to account for one or more deflection angles of the elongate flexible member relative to the fixed support.

15. The method of any one claims 10 to 14, wherein the method includes configuring the force-measuring device to include a planar plate including strain sensors mounted thereon, wherein the strain sensors are configured to provide strain measurement in two substantially mutually orthogonal axes, wherein the plate is configured to experience strains generated from the tension developed in the elongate flexible member that is supported in use on at least a portion of a peripheral region of at least one pulley wheel.

16. The method of claim 15, wherein the method further includes configuring the planar plate for the strains resulting from the tension developed in the elongate flexible member to be linear strains, wherein the force-measuring pulley apparatus is configured to use linear scaling factors to infer orthogonal force components generated by the tension, wherein the inferred orthogonal force components are used in computing a magnitude of the tension.

17. The method of claim 16, wherein the method includes computing the tension as a vector sum of the two substantially orthogonal measurements of strain.

18. The method of any one of claims 10 to 17, wherein the method includes configuring the force-measuring pulley apparatus for at least one of:(i) measuring a physical effort exerted by an athlete when using a cable strength training machine;(ii) measuring a weight of a load when being lifted by a cable crane;(iii) measuring a tension on a halliard of a sailing yacht;(iv) measuring a tension in a drive belt in an automotive engine; and(v) measuring a tension of a catenary wire in an electrified railway.

19. A software product stored on a machine-readable data storage medium, where the software product, when executed on a computing arrangement, is configured to implement the method of any one of claims 10 to 18.

20. The force-measuring pulley apparatus of claim 1, wherein the at least one pulley wheel includes an annular circuit board mounted to a central boss of the at least one pulley wheel, wherein the annular circuit board includes a plurality of electrodes positioned to capacitively couple with a surface of the at least one pulley wheel across a controlled gap, wherein the at least one pulley wheel has an asymmetric structure configured to undergo out-of-plane deformation in response to the developed tension causing displacement of the surface toward or away from theannular circuit board thereby varying the gap, and wherein electronic components of the annular circuit board measure capacitance variations between the electrodes and the surface resulting from the out-of-plane deformation.

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