Patent Description:
<CIT> discloses a magnetostrictive sensor having a sensor head including a driving pole. The sensor head also includes a temperature sensor disposed on the sensor head. <CIT> discloses a torque measuring apparatus. The publication "<NPL>, discloses a magnetostrictive torque sensor.

Magnetostrictive torque sensors are a type of sensor that employs magnetic fields for measuring torque. In general, magnetostriction is a property of ferromagnetic materials that characterizes changes in shape (e.g., expansion or contraction) of the material in the presence of a magnetic field. Conversely, magnetic properties of a ferromagnetic material, such as permeability (the capability to support development of a magnetic field within the material) can change in response to torque applied to the material. A magnetostrictive torque sensor can generate magnetic flux that permeates a shaft and it can sense the magnetic flux as it interacts with the shaft. As an amount of torque applied to the shaft changes, a magnetostrictive sensor can output signals representative of torques applied to the shaft based upon the sensed magnetic flux.

However, magnetic properties of materials can also change due to variations in their temperature. These magnetic property changes can cause variations in the magnetic flux sensed by a magnetostrictive torque sensor that are independent of applied torque. Consequently, torque measurements acquired by magnetostrictive torque sensors based upon sensed magnetic flux can deviate from actual torque on a shaft.

In general, systems and methods are provided for temperature compensation of magnetostrictive sensors, such as torque sensors.

Those skilled in the art will understand that the systems, devices, and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present invention is defined solely by the claims.

Certain exemplary embodiments will now be described to provide an overview of the principles of the structure, function, manufacture, and use of the systems, devices, and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. The features illustrated or described in connection with one exemplary embodiment can be combined with the features of other embodiments.

Magnetostrictive sensors, such as torque sensors, can include a driving element that generates a magnetic flux and a sensing element that measures the magnetic flux as it interacts with a target (e.g., a rotating machine shaft). In some instances, where the temperature of the target can affect torque measurements based upon the sensed magnetic flux, temperature sensors can also be used to measure the target temperature and adjust the torque measurement to compensate for temperature. However, the position of the temperature sensor itself can also decrease accuracy of the torque measurement.

In one aspect, if a temperature sensor is placed too close to a sensing element, it can interfere with the magnetic flux sensed by the sensing element. In another aspect, if a temperature sensor is positioned remotely from a sensing element to avoid this interference, the temperature measured by the temperature sensor can differ from the actual temperature of the target because heat from the target can dissipate over the distance separating it from the temperature sensor. Accordingly, temperature compensated magnetostrictive torque sensors are provided that can integrate a temperature sensor positioned so as to avoid interference with magnetic flux used to measure torque of a target while also remaining sufficiently close to the target for accurately measuring its temperature.

Embodiments of sensing systems and corresponding methods for measuring torque of rotating machine components are discussed herein. However, embodiments of the disclosure can be employed to measure other forces applied to rotating or stationary machine components without limit.

<FIG> illustrates one exemplary embodiment that is not covered by the claims of an operating environment <NUM> containing a temperature compensated torque sensor <NUM> and a target <NUM>. The temperature compensated torque sensor <NUM> can be a magnetostrictive torque sensor including a sensor head <NUM>, a torque sensor <NUM>, a temperature sensor <NUM>, and a controller <NUM>. The torque sensor <NUM> can be positioned within the sensor head <NUM> and it can be configured to generate first signals <NUM> representative of torque applied to a selected portion of the target <NUM>. The temperature sensor <NUM> can be positioned on or adjacent to a distal end 106d of the sensor head <NUM> to facilitate thermal communication with the target <NUM> and it can be configured to generate second signals <NUM> representative of a temperature of the selected portion of the target <NUM>.

In use, the sensor head <NUM> can be positioned proximate to the target <NUM> (e.g., separated by a gap G) for acquiring torque and temperature measurements from the target <NUM>. The controller <NUM> can be configured to receive the first and second signals <NUM>, <NUM>, determine a torque applied to the selected portion of the target <NUM>, and it can use the temperature measurements to adjust the determined torque to compensate for changes in the magnetic properties of the target <NUM> (e.g., magnetic permeability) caused by temperature variations within the selected portion of the target <NUM>. In this manner, the accuracy of the torque measurements can be increased. In certain embodiments, the sensor head <NUM> can be coupled to a frame or other stationary fixture (not shown) to position the sensor head <NUM> at a desired orientation and/or position with respect to the target <NUM> and to maintain the gap G approximately constant. In other embodiments, the torque and temperature measurements can be acquired from the target <NUM> while the target <NUM> is rotating (e.g., about a longitudinal axis A) or while the target is stationary.

As discussed in greater detail below, in certain examples not forming part of the present invention the temperature sensor <NUM> can be separate from the torque sensor <NUM> and mounted to the distal end 106d of the sensor head <NUM>. In embodiments, the temperature sensor <NUM> is integrated with magnetic sensing elements of the torque sensor <NUM>. In either case, the temperature sensor can be configured such that it substantially avoids interfering with magnetic flux sensed by the torque sensor <NUM>. Other embodiments are within the scope of the disclosed subject matter.

<FIG> is a side cross-sectional view of a temperature compensated torque sensing system <NUM> that includes a sensor head <NUM> in electrical communication with a controller <NUM>. The sensor head <NUM> can form a housing <NUM> that contains a torque sensor including a core <NUM>, a driving coil <NUM>, and a sensing coil <NUM>. The sensor head <NUM> can also include a temperature sensor <NUM> coupled to the sensor head <NUM>. As discussed in greater detail below, the torque sensor can be configured to measure torque applied to a selected portion <NUM> of a target <NUM> (e.g., a portion of the target <NUM> positioned opposite the sensor head <NUM> and separated by a gap <NUM>). The temperature sensor <NUM> can be configured to measure the temperature of the target <NUM> concurrently with the torque measurements acquired by the torque sensor.

The target <NUM> can be a component of any machine or equipment <NUM> that is configured to rotate. Examples of rotating components can include, but are not limited to, shafts and rotors. Examples of machines and equipment <NUM> incorporating rotating components can include, but are not limited to, turbomachines (e.g., turbine engines, compressors, pumps, and combinations thereof), generators, combustion engines, and combinations thereof. Force or load can be applied to the target <NUM> by a driver <NUM> (e.g., a reciprocating engine, a combustion engine, a turbine engine, an electrical motor, etc.) to enable the target <NUM> to rotate and drive a load. The target <NUM> can be formed from materials including, but not limited to, ferromagnetic materials such as iron, steel, nickel, cobalt, and alloys thereof. In certain embodiments, the target <NUM> can be non-magnetized. In other embodiments, the target <NUM> can be magnetized.

The core <NUM> can include a base <NUM> and at least two elongated poles <NUM>, <NUM>. The poles <NUM>, <NUM> can extend outwards from the base <NUM> and they can be separated from one another by a selected distance. The core <NUM> can be formed from any ferromagnetic material. Examples can include, but are not limited to, iron, steel, nickel, cobalt, and alloys thereof. One of the poles <NUM> can be a driving pole to which the driving coil <NUM> is wrapped around. The other of the poles <NUM> can be a sensing pole to which the sensing coil <NUM> is wrapped around.

The driving coil <NUM> and the sensing coil <NUM> can each be in electrical communication with the controller <NUM>. As shown in <FIG>, the controller <NUM> can be electrically coupled to an excitation source ES <NUM> by wired or wireless connections. Wireless communication devices, such as radio frequency (RF) transmitters, can be integrated with the controller <NUM> to transmit the signals to an RF receiver integrated with the excitation source ES <NUM>. As also shown in <FIG>, the controller <NUM> can be positioned remotely from the sensor head <NUM>. However, in alternative embodiments (not shown), the controller <NUM> can be positioned within the sensor head <NUM>.

A power source <NUM> (e.g., electrical outlet, electrical generator, battery, etc.) can provide power to the controller <NUM> and the excitation source ES <NUM>. The excitation source ES <NUM> can be configured to deliver a driving current <NUM> (e.g., an AC current) to the driving coil <NUM> and the controller <NUM> can be configured to control characteristics of the driving current <NUM> delivered to the driving coil <NUM> (e.g., frequency, amplitude, etc.) by the excitation source ES <NUM>. The controller <NUM> can be any computing device employing a general purpose or application-specific processor <NUM>. In either case, the controller <NUM> can include memory <NUM> for storing instructions related to characteristics of the driving current <NUM>, such as frequency, amplitude, and combinations thereof. The memory <NUM> can also include instructions and algorithms for integrating sensor signals (e.g., torque signal <NUM> and temperature signal <NUM>) and compensating torque measurements based on the temperature signal <NUM> (e.g., temperature of the target <NUM>). The processor <NUM> can include one or more processing devices, and the memory <NUM> can include one or more tangible, non-transitory, machine-readable media collectively storing instructions executable by the processor <NUM> to perform the methods and control actions described herein.

The driving current <NUM> can pass through the driving coil <NUM> to generate a magnetic flux <NUM>. The magnetic flux <NUM> can permeate the target <NUM>, pass through the sensing coil <NUM>, and return to the driving coil <NUM> via the core <NUM> (e.g., the sensing pole). In this manner, a magnetic loop can be formed through the torque sensor and the target <NUM>.

The sensing coil <NUM> can be used to measure magnetic flux <NUM> exiting the target <NUM>. Because force (e.g., compression, tension, torsion, etc.) applied to the target <NUM> can change the magnetic permeability of the target <NUM>, the magnetic flux <NUM> sensed by the sensing coil <NUM> can change. Thus, the torque applied to the target <NUM> can be determined based on the change in magnetic flux <NUM> received by the sensing coil <NUM> relative to the magnetic flux <NUM> generated by the driving coil <NUM>. The sensing coil <NUM> can be configured to transmit torque signal <NUM> indicative of the changes (e.g., difference) in the magnetic flux <NUM> to the controller <NUM>.

The torque signal <NUM> can be communicated by wired or wireless connections to the controller <NUM> (e.g., receiver <NUM>). As an example, wireless communication devices, such as RF transmitters, can be integrated with the sensor head <NUM> (e.g., proximate to the sensing coil <NUM>) to transmit the signals to an RF receiver integrated with the controller <NUM>. The receiver <NUM> can include electronic components (e.g., amplifiers, filters, etc.) that can condition the torque signal <NUM> before transmitting the torque signal <NUM> to the processor <NUM>. In other embodiments, the torque signal <NUM> can be conditioned after being processed by the processor <NUM>.

Upon receipt of the torque signal <NUM> from the sensing coil <NUM>, the processor <NUM> can process the torque signal <NUM> to calculate the torque applied to the target <NUM>. That is, the processor <NUM> can execute pre-stored and/or user-defined algorithms in the memory <NUM> to calculate the magnitude of the torque applied to the target <NUM> based on the characteristics of the target <NUM>, the sensor head <NUM>, and the driving current <NUM>.

As discussed above, the temperature of the target <NUM> (e.g., temperature at about its outer surface) can affect its magnetic permeability and can in turn affect the torque measurements. Thus, torque measurements determined for the target <NUM> based upon the magnetic flux <NUM> sensed by the torque sensor can deviate from the actual torque applied to the target <NUM>. To address this issue, the temperature of the target <NUM> (e.g., heat <NUM> radiated from the target) can be measured and used to adjust the torque measurements to account for variations in the magnetic properties of the target <NUM> due to temperature changes. In this manner, the temperature sensor <NUM> can improve the accuracy of the torque measurements and enable better control of the machine or equipment <NUM> incorporating the target <NUM>.

The position of the temperature sensor <NUM> relative to the target <NUM> can be selected to facilitate both the torque measurements acquired by the torque sensor and the temperature measurements acquired by the temperature sensor <NUM>. If the temperature sensor <NUM> is positioned too close to the target <NUM>, magnetic flux <NUM> generated by driving coil <NUM> can interact with the temperature sensor <NUM> to a degree that perturbs magnetic flux <NUM> sensed by the sensing coil <NUM>. Alternatively, if the temperature sensor <NUM> is positioned too far from the target <NUM>, a large thermal gradient can be established between the target <NUM> and the temperature sensor <NUM> and temperatures measured by the temperature sensor <NUM> can deviate significantly from the actual temperature of the target <NUM>.

To address one or both of these considerations, the temperature sensor <NUM> can be positioned at a location within a magnetic neutral region <NUM> of the sensor head <NUM> that exhibits a relatively low temperature gradient between the temperature sensor <NUM> and the target <NUM> (e.g., a temperature gradient less than a threshold value). The magnetic neutral region <NUM> can be any region of the sensor head <NUM> that exhibits a magnetic permeability less than the poles <NUM>, <NUM> and the target <NUM> and that does not directly contact the target <NUM>. That is, a greater fraction of the magnetic flux <NUM> can be present outside the magnetic neutral region <NUM> than within the magnetic neutral region <NUM>, decreasing the likelihood of undesirable perturbation of the magnetic flux <NUM>. The magnetic neutral region <NUM> can be located between the driving pole <NUM> and the sensing pole <NUM>. The temperature gradient between the temperature sensor <NUM> and the target <NUM> can be reduced by positioning the temperature sensor <NUM> as close as possible to the target <NUM>, within the boundaries of the magnetic neutral region <NUM>. As shown in <FIG>, the temperature sensor <NUM> can be positioned on a distal end 202d of the sensor head <NUM>.

The temperature sensor <NUM> can be a non-contact sensor that is configured for thermal communication with the target <NUM> and measurement of its temperature without direct contact. Examples of temperature sensors <NUM> can include, but are not limited to, thermoelectric temperature sensors (e.g., thermocouples), pyroelectric temperature sensors, piezoelectric temperature sensors, thermistors (e.g., Pt100), and zick-zack filament wire. In the case of thermoelectric temperature sensors, pyroelectric temperature sensors, and piezoelectric temperature sensors, electrical voltage over the temperature sensor <NUM> can be dependent upon temperature. In the case of thermistor and zick-zack filament wire, electrical resistance of the temperature sensor <NUM> can be dependent upon its temperature. The temperature sensor <NUM> can also include voltage or current sensing circuitry configured to output the temperature signal <NUM> (e.g., a voltage signal or a current signal) to the controller <NUM> for processing.

The temperature signal <NUM> can be combined with the torque signal <NUM> in the receiver <NUM>, thereby generating a combined signal <NUM>. The receiver <NUM> can include electronic components (e.g., amplifiers, filters, etc.) that can condition the temperature signal <NUM> before transmitting the temperature signal <NUM> to the processor <NUM>. In other embodiments, the temperature signal <NUM> can be conditioned after being processed by the processor <NUM>. Similar to the torque signal <NUM> from the sensing coil <NUM>, the temperature signal <NUM> can also be conditioned with electronic components, such as amplifiers, filters, or the like, before or after combining with the torque signal <NUM> or processed by the processor <NUM>. Additionally, in certain embodiments, the signals <NUM>, <NUM> can be combined in the processor <NUM>, rather than in the receiver <NUM>. The memory <NUM> can include instructions and algorithms executable by the processor <NUM> to combine the signals <NUM>, <NUM> and compensate the measured torque based on the measured temperature (e.g., the temperature signal <NUM>). The temperature signal <NUM> may be communicated by wired or wireless connections to the controller <NUM>, as discussed above with respect to the torque signal <NUM>.

<FIG> is a top view of an exemplary embodiment of a torque sensor including a core <NUM> having a cross axis yoke <NUM> with a cross yoke portion <NUM>. Four bases 306a, 306b, 306c, 306d of the cross axis yoke <NUM> can extend radially outward in a plane from the cross yoke portion <NUM>. The four bases 306a, 306b, 306c, 306d can be substantially orthogonal to each other around the cross yoke portion <NUM>. Each of the four bases 306a, 306b, 306c, 306d can extend from the cross yoke portion <NUM> in any configuration and for any length that enables each to operate as described herein. In some embodiments, the cross axis yoke <NUM> can have any number of members, such as <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or more extending radially from the cross yoke portion <NUM>. The bases 306a, 306b, 306c, 306d can be angularly spaced apart by an angle ranging from about <NUM> degrees to <NUM> degrees (e.g., <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, or any combination thereof). As shown in <FIG>, the bases 306a, 306b, 306c, 306d can be angularly spaced apart by approximately <NUM> degrees. Additional embodiments of the sensor head <NUM> and the torque sensor are discussed in <CIT>.

<FIG> illustrate the sensor head <NUM> including another exemplary embodiment of a temperature sensor <NUM>. As shown in <FIG>, the distal end 202d of the sensor head <NUM> can be substantially planar and the temperature sensor <NUM> can take the form of a resistance temperature detector (RTD). The RTD can be an electrically conductive wire (e.g., platinum, copper, etc.) extending within a plane defined by the distal end 202d of the sensor head <NUM> and it can be configured to output a temperature signal based upon its temperature (e.g., heat received from the target).

The RTD temperature sensor <NUM> can be mounted to the sensor head <NUM> in a variety of configurations. In one embodiment, the RTD temperature sensor <NUM> can be coupled to an inner face <NUM> of the distal end 202d of the sensor head <NUM> (<FIG>). In another embodiment, the RTD temperature sensor <NUM> can be coupled to an outer face <NUM> of the distal end 202d of the sensor head <NUM> (<FIG>). In an additional embodiment, illustrated in <FIG>, the distal end 202d of the sensor head <NUM> can be formed as a laminate <NUM> having two or more layers and the RTD temperature sensor <NUM> can be positioned between adjacent layers. In certain embodiments, the RTD temperature sensor <NUM> can be embedded within one or more of the layers. In either case, the shape of the RTD temperature sensor <NUM> can be open-sided (e.g., the free ends of the RTD are not electrically connected). As also shown in <FIG>, the path of the RTD temperature sensor <NUM> can avoid overlying either the driving coil or the sensing coils. That is to say, the RTD can be positioned within the magnetically neutral region. In this manner, the RTD temperature sensor <NUM> can substantially avoid perturbation of magnetic flux sensed by the torque sensor. Furthermore, since the RTD temperature sensor <NUM> can be positioned on or within the distal end of the sensor head <NUM>, heat radiated from the target can be accurately measured by the RTD temperature sensor <NUM> when the sensor head <NUM> is positioned proximate to the target <NUM>.

<FIG> is a side cross-sectional view illustrating an exemplary embodiment of a temperature compensated torque sensing system <NUM>. The temperature compensated torque sensing system <NUM> can be similar to the temperature compensated torque sensing system <NUM> of <FIG> except that it includes a sensing coil <NUM> that is configured to measure both the torque applied to the target as well as the temperature of the target. At least a portion of the sensing coil <NUM> can remain wrapped around the sensing pole <NUM>; however its position on the sensing pole <NUM> can be distally advanced. As shown in <FIG>, a distal end of the sensing coil <NUM> can be positioned at about a free end (e.g., a distal-most end) of the sensing pole <NUM>. In another embodiment, not shown, the distal end of the sensing coil can be positioned distally beyond the free end of the sensing pole <NUM>. In either position, the sensing coil <NUM> can be in thermal communication with the target <NUM> and its temperature can be approximately equal to the target temperature when the sensor head <NUM> is positioned adjacent to the target <NUM>.

<FIG> is a schematic diagram illustrating an electrical circuit <NUM> of the temperature compensated torque sensing system <NUM> according to the invention. The electrical circuit <NUM> includes a torque sensing circuit <NUM> and a temperature sensing circuit <NUM>. The torque sensing circuit <NUM> includes the receiver <NUM> and the sensing coil <NUM>, where the latter can be represented by resistor Ri and inductor L. The temperature sensing circuit <NUM> includes the receiver <NUM>, the sensing coil <NUM>, an additional drive V, and a resistor R<NUM> interposed between nodes <NUM> of the drive V.

The sensor coil <NUM> is formed from a material having an electrical resistance that is dependent upon temperature. The torque sensing circuit <NUM> can operate as discussed above with respect to <FIG>, where the sensing coil can sense magnetic flux <NUM> and output the torque signal <NUM> (e.g., a first alternating current) to the receiver <NUM>. The drive V provides a direct current DC for measuring resistance of the sensing coil <NUM>. This measured resistance is the temperature signal <NUM> and it can be transmitted to the receiver <NUM>. The processor <NUM> can condition and combine the torque signal <NUM> and temperature signal <NUM> to compensate the torque measurement based at least in part on effects of temperature variations on the magnetic permeability of the target <NUM>. Similar to the temperature compensated torque sensing system <NUM>, the torque measurements generated by the temperature compensated torque sensing system <NUM> can be more accurate compared to torque sensing systems that do not have an integrated temperature sensor.

The electrical circuit <NUM> can be configured to avoid interference between the torque signal <NUM> and the temperature signal <NUM>. In the circumstance where direct current DC is provided by the drive V, a portion of the torque sensing circuit <NUM> (e.g., the receiver <NUM>) can be configured to filter this direct current DC so that it does not interfere with the torque signal <NUM>. Similarly, in the circumstance where the second alternating current AC is provided by the drive V, the frequency of the second alternating current can be less than the first alternating current of the torque signal <NUM>. As a result, the second alternating current can be substantially independent of the inductance of the sensing coil <NUM>. That is, the second alternating current can substantially avoid interfering with magnetic flux <NUM> sensed by the sensing coil <NUM>.

The embodiment of <FIG> illustrates the circumstance where measuring the resistance of the sensing coil is voltage driven with voltage measured. However, other combinations are possible, such as current driven with current being measured.

<FIG> is a flow diagram illustrating an exemplary embodiment of a method <NUM> for measuring force (e.g., torque) and temperature of a target using any of the sensing systems discussed herein. The method <NUM> is described below in connection with the temperature compensated torque sensing system <NUM> of <FIG>. However, the method <NUM> is not limited to use with the temperature compensated torque sensing system <NUM> and it can be employed with any magnetostrictive torque sensor and temperature sensor (e.g., <NUM>). In certain aspects, embodiments of the method <NUM> can include greater or fewer operations than illustrated in <FIG> and can be performed in a different order than illustrated in <FIG>.

As shown in <FIG>, in operation <NUM>, a temperature compensated torque sensing system (e.g., <NUM>) can be positioned proximate to a target (e.g., <NUM>). As discussed above, the temperature compensated torque sensing system <NUM> can include the torque sensor and the temperature sensor <NUM>. In operation <NUM>, the temperature compensated torque sensing system <NUM> can be positioned proximate to the target <NUM>. In operations <NUM>-<NUM>, a first magnetic flux can be generated by the torque sensor (e.g., by driving coil <NUM>) and directed through the target <NUM> and the sensing pole <NUM>. In operations <NUM>-<NUM>, a second magnetic flux, representing a net interaction of the first magnetic flux with the target <NUM>, can be detected by the torque sensor (e.g., sensing coil <NUM>, <NUM>) and a first signal (e.g., the torque signal <NUM>) can be output by the torque sensor based upon a second magnetic flux. In operation <NUM>, a second signal (e.g., the temperature signal <NUM>) can be output by the temperature sensor <NUM> based upon a temperature of the target <NUM>. In operation <NUM>, a force (e.g., torque) applied to the target <NUM> can be determined based upon the first signal <NUM> and a temperature of the target <NUM> can be determined based upon the second signal <NUM>. In operation <NUM>, the determined torque can be adjusted based upon the determined temperature.

Exemplary technical effects of the methods, systems, and devices described herein include, by way of non-limiting example, temperature compensation of torque measurements. Integration of one or more temperature sensors into a force sensing system (e.g., a torque sensing system) can provide one or more of the following non-limiting technical effects, in any combination: (<NUM>) Avoiding interference between acquisition of temperature measurements and torque measurements. Separate or stand-alone temperature sensors can be provided in a metallic housing (e.g., stainless steel) that can disturb magnetic fields employed for measuring torque if positioned too close to torque sensors. (<NUM>) Improved accuracy of temperature measurements. If separate or stand-alone temperature sensors are distanced from torque sensors to avoid magnetic interference, the measured temperature can be different than if the temperature sensors are positioned closer to the torque sensor (e.g., closer to the target). (<NUM>) More accurate temperature correction of torque measurements. Acquisition of surface temperatures of a target (e.g., a shaft) more closely to the location where torque signals are measured. (<NUM>) Improved signal to noise ratio of torque and temperature sensing signals. Separate temperature and torque sensing signals brought together through interconnecting cables can pick up noise in the field. (<NUM>) Lower installation cost for one integrated sensor rather than two separate sensors. (<NUM>) Lower development and safety approval certification costs for one integrated sensor rather than two separate sensors. (<NUM>) More appealing design for end users for one integrated sensor rather than two separate sensors.

The subject matter described herein can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed in this specification and structural equivalents thereof, or in combinations of them.

Accordingly, a value modified by a term or terms, such as "about" and "substantially," are not to be limited to the precise value specified.

Claim 1:
A magnetostrictive sensor comprising:
a sensor head (<NUM>,<NUM>) including,
a driving pole having a driving coil (<NUM>) coupled thereto that is configured to generate a first magnetic flux for impinging a target (<NUM>) in response to receipt of a driving current (<NUM>);
a sensing pole (<NUM>) having a sensing coil (<NUM>) coupled thereto that is configured to,
output a first signal component (<NUM>) based at least upon a second magnetic flux resulting from interaction of the first magnetic flux with the target (<NUM>); and
output a second signal component (<NUM>) based upon heat received from the target (<NUM>); and
a controller (<NUM>) in electrical communication with the sensor head (<NUM>,<NUM>) and configured to:
transmit the driving current (<NUM>) to the driving coil (<NUM>);
receive the first and second signal components (<NUM>,<NUM>);
determine a force applied to the target (<NUM>) based upon the first signal components (<NUM>);
determine a temperature based upon the second signal component (<NUM>); and
adjust the force determined from the first signal component (<NUM>) based upon the temperature determined from the second signal component (<NUM>);
characterized by a torque sensing circuit (<NUM>) including a receiver (<NUM>) and the sensing coil (<NUM>) and a temperature sensing circuit (<NUM>) including the receiver (<NUM>), the sensing coil (<NUM>), an additional drive (V) and a resistor (R2) interposed between nodes (<NUM>) of the drive (V) wherein a direct current is provided by the drive (V), the first signal component (<NUM>) being an alternating current and the second signal component (<NUM>) being the direct current provided by the drive (V).