Differential Transfer Case Torque Sensor Apparatus and Method

Abstract

To provide an accurate method for directly and / or indirectly measuring and determining various operation performances and conditions of a vehicle.SOLUTION: A magnetoelasticity active region includes a magnetic adjusted region reversely polarized and having an initial magnetization direction serving as a vertical direction to a sensing direction of a magnetic field sensor pair arranged close to a magnetic active region. In order to accurately measure torque, the magnetic field sensor is specially positioned in a torque transmission member while achieving improved RSU performance and reducing influences of compassing. The torque sensing device is assembled in a vehicle drive train component including a differential component, a transfer case component, a transmission component, and other components such as a transmission shaft in driving, a half shaft, and a wheel, and receives output information useful for controlling the operation of the vehicle by an output signal indicative of vehicle performances being processed in algorithm.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

[0001] Cross-reference of related applications This application is based on, and claims benefits from, the filing dates and disclosures of U.S. Provisional Patent Application No. 62 / 990,270, filed on 16 March 2020, and U.S. Provisional Patent Application No. 62 / 964,946, filed on 23 January 2020, both entitled “Differential Transfer Case Torque Sensor Apparatus and Method.” The contents of both of these provisional applications are incorporated herein by reference in their entirety.

[0002] The present invention relates to a method and sensing device for an automotive transmission, and more particularly to a non-contact magnetorheological torque sensing technology and device for providing a measurement of torque transmitted by transmission components for use in dynamic determination of various vehicle characteristics. [Background technology]

[0003] Sensors are often placed on vehicles to directly or indirectly measure vehicle operating characteristics. For example, wheel slip (relative to the road surface or other surfaces) is a useful operating parameter for understanding the physical mechanics of vehicle operation (i.e., vehicle stability). Vehicle weight is another useful operating parameter for understanding the physical mechanics of vehicle operation and for evaluating vehicle emissions.

[0004] Accurately determining wheel slip, vehicle weight, and numerous other vehicle characteristics is useful for both designers and adjusters, but it is also useful for vehicle operators who need to understand the vehicle's performance, maintenance needs, function, and usage at any given point in time.

[0005] Vehicle performance monitoring may be carried out in part based on manufacturer technical specifications (nominal and / or specified ranges) and third-party technical standards. For example, accurate evaluation of vehicle operating characteristics can be useful in ensuring compliance with predictive maintenance schedules adopted by vehicle manufacturers to ensure appropriate maintenance intervals, and in determining when vehicle functions deviate from nominal or specified ranges. Furthermore, monitoring of vehicle operating characteristics can be useful in ensuring compliance with stringent vehicle fuel consumption and fuel efficiency standards, which are being adopted worldwide and gradually introduced as a result of new government legislation focused on reducing carbon dioxide and other emissions for health and environmental reasons.

[0006] In some cases, regulations may set different standards based on the type and use of the vehicle and the fuel used by it. For example, a commercial truck exceeding a certain gross weight that burns diesel fuel may be required to meet different standards and maintenance schedules than a gasoline-based private passenger vehicle. Therefore, it is important to understand the dynamic characteristics and changes in the vehicle's properties.

[0007] In some cases, it may not be feasible to directly measure vehicle characteristics, and therefore indirect measurement is necessary. For example, consider the process of evaluating vehicle weight. Prior art describes various approaches to vehicle weight (gross vehicle weight and sprung weight) and other operating characteristics. One method for indirectly determining vehicle weight in operation is to use measurements of engine power, vehicle speed, forces acting on the vehicle (e.g., rolling resistance, traction, etc.), and power transmission efficiency. These measurements can be used to calculate the weight (with the assistance of an appropriate algorithm). The calculation may take into account the input force (torque) applied from the vehicle's engine to its transmission drive shaft, the speed of the engine and transmission shaft (revolutions per minute), the weight of the transmission shaft, the wheel size, the vehicle's acceleration, and many other parameters.

[0008] Often, the above and other vehicle parameters relating to vehicle operating characteristics are measured without using feedback from secondary sensors, which would either directly measure the forces transmitted to the drive wheels and provide input to an algorithm to directly calculate the parameters, or provide indirect feedback to verify other direct measurements of the parameters by other sensors.

[0009] Furthermore, vehicle operating characteristics are often measured after the initial detection of inertial motion of components, such as actual wheel rotation, providing feedback to control that motion in the second measurement. If several forces contributing to the change in inertia are detected before the inertial motion occurs, it is beneficial to better understand the vehicle characteristics and control their motion.

[0010] The use of magnetorheologically-based torque sensor devices in vehicles is increasingly common to measure torque-dependent operating characteristics, including the torque applied to power drivetrain components. Some of these power drivetrain components are schematically shown in Figure 1. Figure 1 shows a plan view of the vehicle's drivetrain and differential components 102. These components include a transmission 103, a transfer case 104, a front power transmission drive shaft 105, a front differential 106, a left front half shaft, a right front half shaft, a rear power transmission drive shaft 107, a rear differential 108, and, depending on the vehicle, a left rear half shaft, a right rear half shaft, a left front half shaft, and a right front half shaft.

[0011] Referring to Figure 2A from Patent Document 1, incorporated herein by reference, a shaft-type torque sensor device 2 is shown therein, which comprises a transducer 4 and a magnetic field vector sensor 6. The transducer 4 comprises one or more axially partitioned magnetic continuous oppositely polarized circumferential bands or regions 8, 10 that simply define a magnetically active region or transducer region of the shaft 12. The region 14 on the left side of the shaft, labeled A, and the region 16 on the right side, labeled B, are distinguishable from the active region only in that there is no large residual magnetization. The shaft 12 is typically formed from a ferromagnetic magnetostrictive material having a particularly desirable crystal structure, and thus the active region is also formed from a ferromagnetic magnetostrictive material having a desired crystal structure. A torque 20 applied to one part of the shaft 12 is shown, which is transmitted to another part of the shaft 12, where the motion of the shaft 12 resulting from this torque 20 performs some useful work. The torque 20 is illustrated as rotating clockwise when viewed from the visible end of the shaft 12, but of course, it can be applied to rotate or tend to rotate the shaft in either direction or both, depending on the characteristics of the machine into which the shaft 12 is incorporated.

[0012] The transducer 4 is substantially completely magnetically polarized circumferentially, as taught in Patent Documents 2 and 3. The content and disclosures of these U.S. patents are incorporated herein by reference, at least in that, in the absence of torque 20 (when stationary), the transducer 4 has no net magnetization component in the direction of axis 11 and no net radial magnetization component. The closed cylindrical shape of the transducer 4 enhances the stability of the polarization by forming a complete magnetic circuit.

[0013] The magnetic field vector sensor 6 is a magnetic field vector sensing device positioned and oriented relative to the transducer 4 to sense the magnitude and polarity of the magnetic field generated in space as a result of the reorientation of polarization magnetization from the stationary circumferential direction to a steeper helical direction when a torque 20 is applied. The magnetic field vector sensor 6 generates a signal output that reflects the magnitude of the torque 20. The magnetic field vector sensor 6 may be an integrated circuit Hall effect sensor. A wire 24 connects the magnetic field vector sensor 6 to a current source and transmits the signal output of the magnetic field vector sensor 6 to a receiving device (not shown), such as a control circuit or monitoring circuit for a machine or system incorporating the shaft 12. Further detailed discussions regarding the types, features, positioning, and functions of magnetic field vector sensors are described in at least the aforementioned Patent Documents 2 and 3, and at least the aforementioned Patent Document 4.

[0014] The two circumferentially polarized regions 8 and 10 together constitute the active region 4 of the transducer. The illustrated magnetic field sensor is centered on the “wall” between these two oppositely polarized regions and oriented to sense the radial magnetic field at this location. One or more magnetic field sensors may be used. Generally, each such sensor is positioned near the active region and oriented to be as effective as possible at sensing the magnetic field generated when the shaft transmits torque. The similarities between this transducer and the more conventional designs ("ring sensors") of Patent Documents 2 and 3 that use an active region with uniaxial circumferential anisotropy are obvious.

[0015] Referring to Figure 2B from Patent Document 5, incorporated herein by reference, a substantially disk-shaped torque sensor device is illustrated therein. The disk 110 is formed of a ferromagnetic material and is a magnetoelastically active region 140, or comprises at least a magnetoelastically active region 140. The material selected for forming the disk 110 must be at least ferromagnetic to ensure the presence of magnetic domains to form at least remanent magnetization in the magnetoelastically active region 140, and must be magnetostrictive so that the orientation of magnetic field lines in the magnetoelastically active region 140 can be altered by a stress associated with the applied torque. The disk 110 may be completely solid or partially hollow. The disk 110 may be formed of a homogeneous material or a mixture of materials. The disk 110 may have any thickness, preferably between about 3 mm and about 1 cm.

[0016] The magnetoelastically active region 140 is preferably flat and comprises at least two radially partitioned, annular, oppositely polarized magnetically tuned regions 142, 144 that define the magnetoelastically active region 140 of the torque sensing device. The top surface 112 and bottom surface 114 do not need to be flat as shown and may have variable thickness in a cross-section from the center to the outer edge of the disk 110. Depending on the desired application for the torque sensing device, it may not be practical to position magnetic field sensors 152, 154 on both sides of the disk 110. Therefore, the magnetoelastically active region 140 may be located on only one surface of the disk 110. However, the magnetoelastically active region 140 may be located on both sides of the disk 110. One or more magnetic field vector sensors may be positioned near the magnetically tuned region. [Prior art documents] [Patent Documents]

[0017] [Patent Document 1] U.S. Patent No. 6,260,423 [Patent Document 2] U.S. Patent No. 5,351,555 [Patent Document 3] U.S. Patent No. 5,520,059 [Patent Document 4] U.S. Patent No. 8,087,304 [Patent Document 5] U.S. Patent No. 8,836,458 [Patent Document 6] U.S. Patent No. 4,896,544 [Patent Document 7] U.S. Patent No. 6,047,605 [Patent Document 8] U.S. Patent No. 6,145,387 [Patent Document 9] U.S. Patent No. 6,553,847 [Patent Document 10] U.S. Patent No. 6,513,395 [Patent Document 11] U.S. Patent No. 8,779,306 [Patent Document 12] U.S. Patent No. 9,151,686 [Patent Document 13] U.S. Patent No. 9,683,906 [Patent Document 14] U.S. Patent No. 10,488,278 [Patent Document 15] U.S. Patent No. 10,151,652 [Summary of the Invention] [Problems to be Solved by the Invention]

[0018] A precise method is needed to directly and / or indirectly measure and determine various operating characteristics and conditions using multiple magnetorheological type torque sensors positioned at selected effective locations, in order to provide useful feedback information such as information on vehicle operating characteristics and conditions such as weight, wheel slip, and transmission shifting, as well as sensor feedback information on conditions immediately preceding changes in the vehicle state caused by torque or other forces, rather than relying solely on sensor feedback after the occurrence of inertial motion. [Means for solving the problem]

[0019] In one embodiment, a torque sensing device having a non-contact magnetic field vector sensor positioned near a shaft-like member such as a power transmission shaft or power transmission axle may be used to measure the torque transmitted between the ends of the shaft in order to achieve an accurate evaluation of the amount of torque applied to the transmission drive shaft and the left and right half-shafts connected to the drive wheels. By understanding the torque at those and other locations on the vehicle, the vehicle's operating characteristics can be determined either directly or via feedback so that ridden calculations and, consequently, the vehicle's operation, drivability, and performance can be improved, and it can be predicted when routine, preventative, and other maintenance should be performed.

[0020] Generally, a torque sensor comprises a torque transmission member, an axially partitioned band located within or integrated with a magnetically treated member, and a magnetic flux sensing device for detecting differences in the band's response to a force applied to the torque transmission member without contacting the torque member.

[0021] When torsional stress is applied to the shaft, the magnetization in these bands is reoriented and becomes increasingly helical as the torsional stress increases. The helical magnetization resulting from the twist has both radial and axial components, and the magnitude of the axial component is entirely dependent on the degree of twist.

[0022] In another embodiment, the torque sensor device comprises a torque sensing device having a magnetic field sensor that outputs a signal representing applied torque, the output signal changing in response to a change in applied torque.

[0023] The torque sensor device structure involves the use of a "colorless" transducer, where the magnetoelastically active region is integrated with the shaft, circumferentially polarized, and possesses sufficient magnetic anisotropy to return the magnetization of that region to the circumferential direction when the applied torque decreases to zero after torque is applied to the member. In some configurations, the magnetoelastically active region may be divided into two circumferentially and oppositely polarized regions spaced axially on the shaft, with sensors positioned near each of these regions, having sensing directions oriented axially and oppositely to each other to enable common-mode magnetic field cancellation. In other configurations, it may be useful to divide the magnetoelastically active region into three or more regions, each of which has alternating opposite polarization, and there is at least one sensor in each region.

[0024] Furthermore, the disk-shaped member may be processed to include a magnetoelastically active region that is polarized in the circumferential direction. In such a configuration, magnetic field sensors may be mounted near the active region, and these sensors sense the magnitude of the magnetic field resulting from the torque transmitted from the shaft to the disk-shaped member, and the sensors output a signal in response to the magnitude of the magnetic field. In some such configurations, a disk having two regions polarized in the circumferential and opposite directions may be used, with two sensors positioned along the same radial line, and the sensing directions of these sensors oriented axially and in opposite directions to enable common-mode magnetic field cancellation. In another configuration, it may be useful to use three regions or circular bands, each region or circular band being alternately polarized in opposite directions, with at least one sensor for each band.

[0025] Various improvements have been developed over time in torque sensors to address noise, near-field sources, compassing caused by ambient magnetic fields, parasitic fields, and non-zero RSU signals. Externally originating magnetic fields can arise from both far-field and near-field sources. Far-field sources, such as the Earth's magnetic field, generally have the same effect on each magnetic field sensor in a torque sensing device with multiple magnetic field sensors. Near-field sources, such as permanent magnets, generate magnetic fields with significant local gradients and therefore have significantly different effects on each different magnetic field sensor in a torque sensing device with multiple magnetic field sensors.

[0026] Compassing may also be addressed by using two axially partitioned magnetoelastic active regions polarized in opposite directions, where a magnetic field sensor has opposite axial polarity positioned near the active region and generates an output signal in response to torque applied to the shaft. By summing the outputs of these magnetic field sensors, all common-mode external magnetic fields, i.e., far-field fields, are canceled out. In applications employing such a method, the oppositely polarized sensors should be placed as close to each other as possible to maintain the efficiency of the common-phase rejection scheme. Sensors that are spaced far apart exhibit reduced common-phase rejection efficiency because the Earth's magnetic field can be significantly distorted in and around the ferromagnetic parts of the torque sensor.

[0027] To cancel near-field magnetic noise from an external source without canceling the torque-induced magnetic field, the torque sensor may comprise three sets of magnetic field sensors spaced axially apart near the shaft, the shaft having a magnetoelastically active region that is polarized in the circumferential direction. The signals received by each of the magnetic field sensors are tuned to compensate for the effects of the near-field source.

[0028] In another embodiment, the torque sensor device of the type described above comprises torque sensing devices having magnetic fields arranged in pairs, wherein these magnetic field sensors have opposite sensing directions to minimize the adverse effects of magnetic noise, including compassing.

[0029] In another embodiment, the torque sensing device has a plurality of spaced-apart magnetic field sensors, which are specifically positioned to enhance the performance of the torque sensing device.

[0030] In yet another embodiment, the torque sensor may be configured such that the magnetoelastic active region of the shaft-shaped member of the torque sensor device has both ferromagnetic and magnetostrictive properties, the magnetoelastic active region generates a magnetic field that fluctuates with the torque applied to the shaft member, and the magnetoelastic active region has sufficient magnetic anisotropy to return the magnetization within the magnetoelastic active region to its initial state when the torque applied to the shaft member decreases to zero.

[0031] In another configuration, at least one pair of magnetic field sensors are arranged adjacent to each other and near the magnetoelastically active region, and the sensing directions of the magnetic field sensors are opposite to each other and can be perpendicular to the polarization directions of the first and second magnetically tuned regions, such that the magnetic field sensors generate output signals representing the torque applied to the shaft member.

[0032] In yet another configuration, the magnetically tuned region of the torque sensor device may be part of a shaft-like member, and these tuned individual regions or bands may not have gaps between them, thereby potentially increasing the accuracy of the torque sensing device.

[0033] Furthermore, multiple pairs of magnetic field sensors may be used at specific sensing locations to improve the accuracy of the output signal used to determine (calculate) the torque.

[0034] In another embodiment, the magnetoelastically active region may be magnetized axially rather than circumferentially. Furthermore, the magnetic field sensor may therefore be oriented circumferentially if the magnetoelastically active region or the individual magnetically tuned regions or magnetically tuned bands constituting the magnetoelastically active region are polarized axially, or oriented axially if the magnetically tuned regions are polarized circumferentially, in order to enhance the performance and increase the accuracy of the device.

[0035] In another embodiment, the torque sensor devices of the types described above and their variations may be used in conjunction with the power transmission drive shaft of a vehicle to output a signal representing the actual torque applied / transmitted by the shaft at the position where the magnetic field sensor is located.

[0036] Furthermore, a torque sensor device may be used in conjunction with the left half-shaft rear axle, and a different torque sensor device may be used in conjunction with the right half-shaft rear axle of the vehicle. Each of these torque sensor devices is used to output a signal representing the actual torque applied / transmitted by the half-shaft at the position where the magnetic field sensor is located, in order to improve the operation of the drivetrain and the vehicle in which the drivetrain is part, by using it as input to an algorithm that estimates parameters associated with the drivetrain.

[0037] Generally, the torque output to each half-shaft in a differential is equal to the torque input to the differential, as shown in equation (1).

[0038] T(left)+T(right)=T(input) (1)

[0039] Here, the input torque T(input) may be the torque measured by one or more torque sensors applied to the power transmission shaft at, for example, the position where one end of the power transmission shaft is closest to the rear differential, the position where the other end of the power transmission is closest to the transfer case or engine or motor, or a position between the two ends of the power transmission shaft.

[0040] In some cases, the calculation of torque at the drive wheels or other locations may be performed by estimating specific losses or efficiencies between the point where power is generated (i.e., output from the engine / motor) and the point where power is applied (e.g., the drive wheels or some intermediate point) when actual data illustrating actual losses or efficiencies are unavailable. One or more torque sensors of the types described herein, positioned between the point where power is generated and the point where power is applied, may enable a more accurate assessment of the losses and efficiencies of the power transmission system, as well as better vehicle management.

[0041] In another embodiment, system-level output signals from multiple torque sensor devices positioned at various locations within the vehicle may be used as input to an algorithm for calculating one or more operating conditions of the vehicle, including but not limited to calculating the total weight of the vehicle. Weight can be estimated from, among other parameters, the gradient angle at the location where the vehicle is positioned, the wheel torque relative to the gradient angle, the drive wheel turning radius, the gravity constant, and the road load torque measured at the drive wheels. Vehicle mass may include the mass of the vehicle, the mass of any additional occupants, and the mass of any trailers coupled to the vehicle. Knowing the total mass of the vehicle at any given time and under various conditions may be important for several reasons, including the purpose of accurately managing the power output of the engine or motor.

[0042] Other uses of signals from torque sensor devices include, among other things, estimating friction at the wheels (i.e., microslip), generating inputs to traction control systems, braking systems, and transmission shift systems, monitoring vehicle dynamics such as torque distribution to the right, left, front, and rear wheels in a four-wheel drive system, generating inputs to overload protection systems, predictive maintenance monitoring algorithms, and warranty claim protection analysis (e.g., monitoring for engine tuning), and providing data to a hybrid drive torque management system.

[0043] The features of the present invention can be better understood by referring to the following detailed description of the invention, the appended claims, and the various drawings accompanying this specification, along with these and other aspects, purposes, advantages, and features of the invention that may become apparent thereafter. [Brief explanation of the drawing]

[0044] [Figure 1] This is a schematic plan view of drivetrain and differential components for use in a vehicle. [Figure 2A] This is a schematic perspective view of the components of a prior art shaft-type torque sensor system. [Figure 2B] This is a schematic perspective view of the components of a prior art disk-type torque sensor system. [Figure 3A] This is a schematic perspective view of the mechanical components of a rear differential for use in a vehicle. [Figure 3B] This is a schematic perspective view of the mechanical components of a rear differential for use in a vehicle. [Figure 4] This is a schematic diagram of a torque sensor device connected to the left rear half-shaft shaft, and several parts of the vehicle's rear differential. [Figure 5] This is a schematic diagram of a torque sensor device connected to a half-shaft shaft for a vehicle. [Figure 6] This is a schematic diagram of a torque sensor device connected to a vehicle's half-shaft. [Figure 7] This is another schematic diagram of a torque sensor device connected to a vehicle half-shaft. [Figure 8] This is a schematic cross-sectional perspective view of a torque sensor device and rear transfer case for a vehicle. [Figure 9] This is another schematic cross-sectional perspective view of a torque sensor device and transfer case for a vehicle. [Figure 10]This is a schematic cross-sectional view of a torque sensor device for a vehicle's transmission drive plate. [Figure 11] Figure 9 shows a schematic cross-sectional view of a torque sensor device for a vehicle and a modified transmission. [Figure 12] This is a schematic diagram showing some of the vehicle components monitored by one or more torque sensor devices. [Figure 13] This is a schematic diagram showing drivetrain and differential components for use in a vehicle, along with individual torque sensors. [Modes for carrying out the invention]

[0045] Several preferred embodiments of the present invention are described for illustrative purposes, but the present invention may also be embodied in other forms not specifically shown in the drawings. These drawings are presented herein for illustrative purposes only and are not to scale.

[0046] Device

[0047] Referring now to Figure 3A, a schematic perspective view is shown therein, illustrating some of the mechanical components of a rear differential unit 302 for use in a vehicle (not shown). The configuration of the components of this rear differential unit 302 is generally also applicable to a front differential unit of a vehicle adapted for all-wheel drive. As shown, the rear differential unit 302 comprises all or part of a power transmission shaft 304, which comprises a drive pinion gear 306, a crown gear wheel 308, a bevel gear 310, some parts of a left rear half shaft shaft 312, and some parts of a right rear half shaft shaft 314.

[0048] The power transmission shaft 304 is a shaft having a predetermined length and diameter and made from a material suitable for a particular vehicle application. The power transmission shaft 304 may be formed from a homogeneous material or from a mixture of materials. The power transmission shaft 304 may be completely solid or partially hollow. The power transmission shaft 304 is used to transmit power generated by the vehicle's engine or motor (not shown) to other components of the rear differential unit 302 by applying torque T(shaft) to the shaft 304 at the near end of the shaft 304 (the end closest to the power source). This torque is then transmitted along the shaft to the distal end shown in the figure.

[0049] The pinion gear 306 is located at the distal end of the power transmission shaft 304 and is used to engage with the crown gear wheel 308. The crown gear wheel 308 is connected to one end of the left rear half shaft 312. The other end of the left rear half shaft 312 (not shown) is mechanically operably connected (e.g., by bolting, welding, screwing, bonding, pinning, or other means) to the corresponding wheel (also not shown), which in this case is the left rear wheel of the vehicle.

[0050] The crown gear wheel 308 may be completely solid or partially hollow. The crown gear wheel 308 may be formed from a homogeneous material or from a mixture of materials. The crown gear wheel 308 engages with the bevel gear 310.

[0051] The bevel gear 310 is mechanically operably connected to one end of the right rear half-shaft shaft 314. The other end of the right rear half-shaft shaft 314 is mechanically operably connected to the corresponding wheel (not shown), which in this case is the right rear wheel of the vehicle.

[0052] A shaft-type primary non-contact torque sensor 316 having one or more of the above-described features and embodiments appropriately modified for a specific application may be used. Specifically, the torque sensor 316 may comprise a transducer portion having one or more axially partitioned magnetic continuous reverse circumferentially polarized bands or regions 8, 10 that simply define a magnetically active region or transducer region of the shaft, together with one or more magnetic field vector sensors (shown in Figure 2A as a non-limiting example).

[0053] The torque sensor 316 may be positioned at the distal end of the power transmission shaft 304 near the pinion gear 306, as roughly illustrated, or at other locations closer or further away than those shown. Additional similar (or structurally different but functionally identical) primary non-contact torque sensors 318, 320 may be positioned on the right rear half-shaft axis 314 and the left rear half-shaft axis 312, respectively, at the roughly illustrated locations or at other locations on the half-shafts. In some examples, only the torque sensor 316 may be part of the rear differential device 302. In other examples, only the torque sensors 318, 320 may be part of the rear differential device 302. In some examples, all three torque sensors may be included, but only the torque sensor 316 or only the torque sensors 318, 320 may operate in the normal use of the rear differential device 302.

[0054] In the illustrated configuration, the torque applied to the power transmission shaft 304 can be split and converted into torques applied to the left rear half-shaft shaft 312 and the right rear half-shaft shaft 314. These left rear half-shaft shafts 312 and right rear half-shaft shafts 314 are mechanically operable to the left rear wheel and the right rear wheel. The torques output to each of the half-shaft shafts 312 and 314 can be correlated with the torque input to the differential using the following general relationship.

[0055] T316 = 1 / ε d ×(T318+T320) (2)

[0056] Here, T316 is the applied torque measurement provided by the power transmission shaft 304 at the position of torque sensor 316, T318 is the applied torque measurement at the right rear half shaft 314 at the position of torque sensor 318, T320 is the applied torque measurement at the left rear half shaft 312 at the position of torque sensor 320, ε d This represents mechanical inefficiencies in the differential (which may include temperature changes resulting from material interactions, deformation, sliding, and other losses between gears).

[0057] All or some of the torque sensors shown may be located inside or outside the differential housing 322 (circularly shown as a box in Figure 3A). Furthermore, additional torque sensors may be positioned closer to these wheels and at other locations along the power transmission shaft 304, as needed, to improve the ability to accurately measure and evaluate torque at these wheels and other locations without the need to rely on estimates of efficiency and other factors associated with the delivery of power (generated by the vehicle's motor or engine) to the drive wheels.

[0058] The magnetoelastic active regions of the torque sensors 316 and 318 may include one or more magnetically tuned bands or magnetically tuned regions 8, 10 in the roughly illustrated positions, formed by magnetically tuned continuous axially extending portions of the power transmission shaft 304, the left rear half-shaft shaft 312, and / or the right rear half-shaft shaft 314. The actual placement of these magnetically tuned bands or magnetically tuned regions 8, 10 may be determined by physical space, temperature, environment, and other considerations. The tuned bands or tuned regions 8, 10 may be formed before the shaft is installed in the vehicle, for example, by exposing the portions to strong permanent magnets in an orientation that imparts magnetization to those portions in a nearly circumferential direction or in alternating different circumferential directions (regions 8, 10, as best seen in Figure 2A). One, two, three, or more such tuned regions may be provided as part of the magnetoelastic active transducer portion of the shaft. In some applications, these regions may be formed from polycrystalline material. In one embodiment, this portion of the magnetized shaft may be made of a polycrystalline material that exhibits cubic symmetry and sufficient saturation coercivity (e.g., greater than 15 Oelested) and roughly shows the properties of a randomly oriented dipole before magnetization.

[0059] Each of the torque sensors 316, 318, and 320 may have one or more magnetic field vector sensors. For example, torque sensor 316 may include magnetic field sensors 316-1 and 316-2 arranged circumferentially at the same magnetically tuned axial position on the power transmission shaft 304, with each sensor spaced by an azimuth angle of 180 degrees (i.e., located on both sides of the power transmission shaft 304 in the magnetically tuned band or magnetically tuned region 8). Furthermore, additional magnetic field sensors 316-3, 316-4, etc. (not shown) may be used at the same axial position, with each sensor spaced by an equal azimuth angle (e.g., 90 degrees in the case of four magnetic field sensors). A further number of magnetic field sensors may be positioned at different axial positions corresponding to different tuned bands or magnetically tuned regions 10 of the magnetoelastic active region of the shaft, with each sensor arranged circumferentially and spaced by a certain azimuth angle.

[0060] Similarly, the torque sensor 318 located on the right rear half-shaft 314 may also include magnetic field sensors 318-1 and 318-2 arranged circumferentially at the same axial position on the right rear half-shaft 314, which are magnetically tuned, and each sensor is spaced by an azimuth angle of 180 degrees. Furthermore, additional magnetic field sensors 318-3, 318-4, etc. (not shown) may be used, each sensor being spaced by an equal azimuth angle (e.g., 90 degrees in the case of four magnetic field sensors). Further magnetic field sensors may be positioned at different axial positions corresponding to the magnetically tuned band or magnetically tuned region 10 of the magnetoelastically active region of the right rear half-shaft 314, each sensor similarly arranged circumferentially and spaced by a certain azimuth angle.

[0061] Similarly, the torque sensor 320 may also include magnetic field sensors 320-1 and 320-2 arranged circumferentially at the same axial position on the left rear half shaft 312, each sensor spaced by an azimuth angle of 180 degrees. Furthermore, additional magnetic field sensors 320-3, 320-4, etc. (not shown) may be used, each sensor spaced by an equal azimuth angle (e.g., 90 degrees in the case of four magnetic field sensors). Further magnetic field sensors may be positioned at different axial positions corresponding to the magnetically tuned band or magnetically tuned region 10 of the magnetoelastically active region of the left rear half shaft 312, each sensor similarly arranged circumferentially and spaced by a certain azimuth angle.

[0062] Each magnetic field sensor is positioned to sense the magnitude and polarity of the magnetic field emanating from the magnetically tuned band or magnetically tuned region 8, 10 in the space surrounding the transducer as a result of the reorientation of the polarization magnetization from the stationary circumferential direction to a steeper helical direction upon torque application. These magnetic field sensors generate a signal output that reflects the magnitude of the torque.

[0063] Each of the magnetic field sensors may be an integrated circuit Hall effect sensor. Each magnetic field sensor may be connected to a current source by lead wires or electrical wires 24 (as shown in Figure 2A) to provide voltage to the magnetic field sensor components, and may transmit the signal output of the magnetic field sensor to a receiving device (not shown), such as an electrical control unit which may include monitoring circuits, signal conditioning circuits, amplification circuits, or other circuits.

[0064] In addition to the primary magnetic field sensors 316, 318, and 320, one or more secondary magnetic field sensors (not shown) may be used to evaluate the effects of near-field or far-field sources based on the output signals from the torque sensors 316, 318, and 320. For example, one or more secondary magnetic field sensors may be positioned axially remote from the left and right boundaries of their respective magnetoelastic active regions to detect the presence of near-field and far-field sources at the locations of the torque sensors 316, 318, and 320.

[0065] Magnetic elastic and magnetostrictive non-contact torque sensors, illustrated for use with rotating shafts or disk-shaped members, are commercially available from Methode Electronics, Inc. (Chicago, Illinois) and are illustrated and described in the following documents, namely, Garshelis (and et al.) Patent Documents 1-3 and 6-9, Jones Patent Document 10, Lee Patent Document 11, and Gieβibl (and et al.) Patent Documents 12-15, all of which are incorporated herein by reference in their entirety.

[0066] In another exemplary configuration shown in Figure 3B, the crown gear wheel 308 may include a disc-type primary non-contact torque sensor 322 having one or more of the features and embodiments described above in relation to Figure 2B. Specifically, the torque sensor 322 may include a magnetorheologically strainable magnetorheologically active region 340 such that the orientation of magnetic field lines within the magnetorheologically active region 340 can be altered by a stress associated with the applied torque (for example, the torque applied by the engagement between the pinion gear 306 portion of the power transmission shaft 304 and the gear portion 309 of the crown gear wheel 308).

[0067] The magnetoelastic active region 340 may be flat (or may have the same contour as a portion of the crown gear wheel 308, which is partly formed by the magnetoelastic active region 340), and comprises at least two radially partitioned, annular, oppositely polarized magnetically tuned bands or magnetically tuned regions 342, 344 that define the magnetoelastic active region 340 of the torque sensor 322. These bands or regions 342, 344 may have a variable thickness in cross-section and a variable width in the radial direction from the center to the outer edge of the crown gear wheel 308.

[0068] The torque sensor 322 may have one or more magnetic field vector sensors. For example, the torque sensor 322 may include magnetic field sensors 322-1 and 322-2 positioned circumferentially above the surface of a tuned band or magnetically tuned region 342 on the crown gear wheel 308, at the same distance from the rotation axis of the crown gear wheel 308 and magnetically tuned, with each magnetic field sensor spaced by a certain azimuth angle. Additional magnetic field sensors may be used at the same radial position, with each sensor spaced by an equal azimuth angle (e.g., 90 degrees in the case of four magnetic field sensors). A further number of magnetic field sensors may be positioned at different axial positions corresponding to other tuned bands or magnetically tuned regions 344 of the magnetoelastic active region 340, with each sensor positioned circumferentially and spaced by a certain azimuth angle.

[0069] In some examples, only the torque sensor 322 may be part of the rear differential device 302. In yet another example, some or all of the torque sensors 316, 318, and 320 may be part of the rear differential device 302. In some examples, there may be four torque sensors in various combinations, some of which may operate during normal use of the rear differential device 302.

[0070] Referring to Figure 4, a partial schematic diagram of several torque sensor devices used in conjunction with the rear differential device 402 for the vehicle is shown therein. Similar to the configuration described above in Figure 3A, the rear differential device 402 encompasses a portion of the power transmission shaft 404, which includes a drive pinion gear 406, a crown gear wheel 408, a bevel gear 410, a connecting end portion of the left rear half shaft (not shown), and a connecting end portion of the right rear half shaft 414 located at its distal end.

[0071] The right rear half-shaft axle 414 consists of a wheel hub connecting end 416, a shaft 418, a rear differential connecting end 420, and an inward constant velocity (CV) joint 422 and an outward constant velocity (CV) joint 424. As shown in the figure, the hub end portion 416 of the axle 414 may be equipped with a torque sensor 426, and the differential end portion 420 of the axle 414 may be equipped with a torque sensor 430. In some examples, both torque sensors 426 and 430 may be provided on the right rear half-shaft axle 414, and one or both of them may be operated during normal use.

[0072] Each of the torque sensors 426 and 430 may be provided with a magnetically tuned area of ​​the type described above, each having one, two, three, or more magnetically tuned bands or magnetically tuned areas (not shown) that generate an external field in the space above the magnetically tuned band or magnetically tuned area resulting from the torque applied to the right rear half-shaft axis 414.

[0073] Each of the torque sensors 426 and 430 may include one or more magnetic field vector sensors, as roughly illustrated and described above, to sense the magnitude and polarity of the aforementioned external field and generate a signal output that reflects the magnitude and direction of the applied torque. The magnetic field sensors may include a pair of opposingly connected sensing coils to measure the differential signal resulting from the external magnetic flux of the polarization band of the magnetically tuned band or magnetically tuned region.

[0074] For example, the torque sensor 426 may include magnetic field sensors 426-1 and 426-2 positioned circumferentially above the surface of a magnetically tuned band or magnetically tuned region of the wheel hub connecting end 416, at the same radial distance from the rotation axis of the wheel hub connecting end 416 and magnetically tuned. Each magnetic field sensor 426-1, 426-2 may be spaced by a specific azimuth angle, such as 180 degrees. Furthermore, additional magnetic field sensors may be used at the same radial position, each sensor spaced by an equal azimuth angle (e.g., 90 degrees in the case of four magnetic field sensors). A further number of magnetic field sensors may be positioned at different axial positions corresponding to other tuned bands or magnetically tuned regions of the magnetoelastic active region, each sensor positioned circumferentially and spaced by a specific azimuth angle.

[0075] Similarly, the torque sensor 430 may include magnetic field sensors positioned circumferentially above the surface of the magnetically tuned band or magnetically tuned region of the rear differential connecting end 420, at the same radial distance from the rotation axis of the rear differential connecting end 420 and magnetically tuned. Each magnetic field sensor (not shown) may be spaced by a specific azimuth angle, such as 90 degrees (for four magnetic field sensors) or 180 degrees (for two magnetic field sensors). A further number of magnetic field sensors may be positioned at different axial positions corresponding to other tuned bands or magnetically tuned regions of the magnetoelastic active region, each sensor being circumferentially positioned and spaced by a specific azimuth angle.

[0076] In the illustrated configuration, the torque supplied by the power transmission shaft 404 is partially transmitted and applied to the rear differential connecting end 420 of the right rear half-shaft shaft 414, which is then applied to the inner CV joint 422, then to the shaft 418, then to the outer CV joint 424, and finally to the wheel hub connecting end 416 (and finally to the right rear wheel). The torque measured by torque sensors 426 and 430 is used to reduce the mechanical inefficiency (ε) in the CV joint. cvWhile considering losses including ), the correlation can be roughly shown below.

[0077] T430 = f × T316 (3)

[0078] T426 = 1 / ε cv ×T430 (4)

[0079] Here, T316 is the measured value of the applied torque provided by the power transmission shaft 304 at the location of the torque sensor 316 (shown in Figure 3), T430 is the measured value of the applied torque at the rear differential connecting end 420 at the location of the torque sensor 430, f is the ratio of the torque transmitted to the right rear half shaft 414 by the differential (e.g., 0% to 100%), T426 is the measured value of the applied torque at the wheel hub connecting end 416 at the location of the torque sensor 426, and ε cv This represents mechanical inefficiencies in a CV joint (which may include temperature changes due to material interactions, deformation, sliding, and other factors).

[0080] In another embodiment, the crown gear wheel 408 may be provided with a magnetically tuned region 440 on its outer circumferential surface, which may consist of one or more bands or regions that are polarized in substantially alternating circumferential directions. Corresponding non-contact magnetic field vector sensors 440-1, 440-2, ... 440-n (where 440-n indicates that the desired number of magnetic field sensors is n and this is the nth sensor) may be positioned around the magnetically tuned region 440 at various substantially equal azimuth angles near each of the polarization bands or regions in a manner similar to that described above.

[0081] Referring to Figure 5, a schematic diagram of another half-shaft axle device 502 for a vehicle is shown therein. In this embodiment, the half-shaft axle 502 consists of a wheel hub connecting portion 504, an outward CV joint or other type of joint 506 (in this case surrounded by a protective flexible boot), a shaft 508, and a differential connecting portion 510.

[0082] As shown in the figure, a portion of the shaft near the wheel hub coupling portion 504 may be equipped with a torque sensor 514, and a portion of the shaft near the differential coupling portion 510 may be equipped with a torque sensor 512. In some examples, both torque sensors 512 and 514 may be equipped on the half-shaft shaft 502, and one or both of these torque sensors may be operated during normal use. As described above, each torque sensor 512 and 514 may be provided with a magnetically tuned region, each of which may consist of one or more bands or regions that are polarized in substantially alternating circumferential directions.

[0083] As further illustrated, corresponding non-contact magnetic field vector sensors 512-1, 512-2, ... 512-n may be positioned at a specific axial position and circumferentially spaced around a magnetically tuned region at various substantially equal azimuth angles near each of the polarization bands or regions of the torque sensor 512 to measure external magnetic flux from the polarization band or region when torque is applied. Similarly, non-contact magnetic field vector sensors 514-1, 514-2, ... 514-n may be positioned around a magnetically tuned region at various substantially equal azimuth angles near each of the polarization bands or regions of the torque sensor 514 (again, n represents the desired number of magnetic field sensors).

[0084] In the illustrated configuration, the torque supplied by the power transmission shaft (which may be the power transmission shaft 304 or the front-wheel drive power transmission shaft) is partially transmitted and applied to the differential coupling portion 510 of the half-shaft shaft device 502, which is then applied to the shaft 508, then to the outer CV joint 506, and finally to the wheel hub coupling end 504 (and finally to the wheel). The torque measured by the torque sensors 512 and 514 is used to reduce the mechanical inefficiency (ε) in the CV joint. cv While considering losses including ), the correlation can be roughly shown below.

[0085] T510 = f × T - input (5)

[0086] T514 = 1 / ε cv ×T512 (6)

[0087] Here, T-input is the applied torque supplied by the power transmission shaft, measured at the nearest torque sensor on the shaft; T512 is the measured applied torque at the differential coupling portion 510 at the location of torque sensor 512; f is the ratio of the torque transmitted to the half-shaft shaft device 502 by the differential (e.g., 0% to 100%); T514 is the measured applied torque at the wheel hub coupling end 504 at the location of torque sensor 514; ε cv This represents the type of mechanical inefficiency described above that arises from CV joints.

[0088] Referring to Figure 6, a schematic diagram of another half-shaft axle device 602 for a vehicle is shown therein. In this embodiment, the half-shaft axle 602 consists of a wheel hub connecting portion 604, an outward CV type or other type joint 606 (equipped with a protective flexible boot), a shaft 608, an inward CV type or other type joint 616, and a differential connecting portion 610.

[0089] As shown in the figure, a portion of the shaft near the wheel hub coupling portion 604 may be equipped with a torque sensor 614, and a portion of the shaft near the differential coupling portion 610 may be equipped with a torque sensor 612. In some examples, both torque sensors 612, 614 may be equipped on the half-shaft shaft 602, and one or both of these torque sensors may be operated during normal use. As described above, each torque sensor 612, 614 may be provided with a magnetically tuned region, each of which may consist of one or more bands or regions that are polarized in substantially alternating circumferential directions. Corresponding non-contact magnetic field vector sensors 612-1, 612-2, ... 612-n may be positioned around the magnetically tuned region at various substantially equal azimuth angles near each of the polarization bands or regions of the torque sensor 612. Similarly, non-contact magnetic field vector sensors 614-1, 614-2, ... 614-n may be positioned around the magnetically tuned region at various substantially equal azimuth angles near each of the polarization bands or polarization regions of the torque sensor 614 (where again n represents the desired number of magnetic field sensors).

[0090] In the illustrated configuration, the torque supplied by the power transmission shaft (which may be the power transmission shaft 304 or the front-wheel drive power transmission shaft) is partially transmitted and applied to the differential coupling portion 610 of the half-shaft shaft unit 602, which is then applied to the inner CV joint 616, then to the shaft 608, then to the outer CV joint 606, and finally to the wheel hub coupling end 604 (and finally to the wheel). The torques measured by the torque sensors 612 and 614 can be correlated as roughly shown below, taking into account losses as described above.

[0091] T610 = f × T - input (7)

[0092] T614 = 1 / εcv ×T612 (8)

[0093] Here, T-input is the applied torque supplied by the power transmission shaft as measured at the position of the nearest torque sensor, T612 is the measured value of the applied torque at the differential connection portion 610 at the position of the torque sensor 612, f is the ratio of the torque transmitted to the half shaft axis device 602 at the differential (e.g., 0% - 100%), T614 is the measured value of the applied torque at the wheel hub connection end portion 604 at the position of the torque sensor 614, ε cv represents the total or combination of mechanical inefficiencies in the CV joint.

[0094] Next, referring to FIG. 7, a schematic view of another half shaft axis device 702 for a vehicle is shown there. In this embodiment, the half shaft axis 702 consists of a wheel hub connection portion 704, an outer CV joint or other type of joint 706 (with a protective flexible boot), a shaft 708, a U joint 716, and a differential connection portion 710.

[0095] As shown in the figure, a portion of the shaft near the wheel hub coupling portion 704 may be equipped with a torque sensor 714, and a portion of the shaft near the differential coupling portion 710 may be equipped with a torque sensor 712. In some examples, both torque sensors 712, 714 may be equipped on the half-shaft shaft 702, and one or both of these torque sensors may be operated during normal use. As described above, each torque sensor 712, 714 may be provided with a magnetically tuned region, each of which may consist of one or more bands or regions that are polarized in substantially alternating circumferential directions as previously described. Corresponding non-contact magnetic field vector sensors 712-1, 712-2, ... 712-n may be positioned around the magnetically tuned region at various substantially equal azimuth angles near each of the polarization bands or regions of the torque sensor 712. Similarly, non-contact magnetic field vector sensors 714-1, 714-2, ..., 714-n may be positioned around the magnetically tuned region at various substantially equal azimuth angles near each of the polarization bands or regions of the torque sensor 714 (again, n represents the desired number of magnetic field sensors).

[0096] In the illustrated configuration, the torque supplied by the power transmission shaft (which may be the power transmission shaft 304 or the front-wheel drive power transmission shaft) is partially transmitted and applied to the differential coupling portion 710 of the half-shaft shaft unit 702, which is then applied to the U-joint 716, then to the shaft 708, then to the inner CV joint 706, and finally to the wheel hub coupling end 704 (and finally to the wheel). The torques measured by the torque sensors 712 and 714 can be correlated as roughly shown below, taking into account losses as described above.

[0097] T710 = f × T - input (9)

[0098] T714 = 1 / ε cv ×T712 (10)

[0099] Here, T-input is the applied torque supplied by the power transmission shaft, measured at the nearest torque sensor location; T712 is the measured applied torque at the differential coupling portion 710 at the location of torque sensor 712; f is the ratio of the torque transmitted to the half-shaft shaft device 702 via the differential (e.g., 0% to 100%); T714 is the measured applied torque at the wheel hub coupling end 704 at the location of torque sensor 714; ε cv This represents the total or combination of mechanical inefficiencies in CV joints and U joints.

[0100] Next, referring to Figure 8, a schematic cross-sectional perspective view of a vehicle transfer case device 802 is shown there. This transfer case device 802 includes a portion of the power transmission shaft 804 within the transfer case housing 806.

[0101] The illustrated portion of the power transmission shaft 804 may be solid or partially hollow and may have a diameter D of approximately 30 mm. The shaft 804 may also include a torque sensor 808 comprising a portion of the power transmission shaft 804, which is given a magnetically tuned region 810 that is integral to the portion of the shaft and extends circumferentially around the shaft and radially within the shaft for a distance from the surface forming a transducer portion of substantially uniform thickness d. The magnetically tuned region 810 may be fabricated in the portion of the power transmission shaft which is a ferromagnetic material including carbon steel, and may comprise one, two, three, or more alternating circumferentially polarized bands or regions (only two bands are shown, which are substantially circumferentially polarized in the directions roughly indicated by the arrows).

[0102] Corresponding non-contact magnetic field vector sensors 812-1, 812-2, ... 812-n (only two are shown) can be arranged circumferentially around one of the polarization bands or regions at various substantially equal azimuth angles in the same axial position (for example, a pair of two sensors arranged at a 180-degree azimuth angle). Similarly, non-contact magnetic field vector sensors 814-1, 814-2, ... 814-n (only two are shown) can be arranged circumferentially around the other of the polarization bands or regions at various substantially equal azimuth angles in a different axial position from magnetic field sensor 812.

[0103] The magnetic field sensors 812, 814 in each group are generally oriented in pairs such that an external magnetic flux is generated from the magnetically tuned region 810 by the torque applied to the power transmission shaft 804. These magnetic field sensor pairs have sensing directions set to determine the rotational direction of the power transmission shaft 804 and the magnitude of the torque applied to the shaft. Additional secondary magnetic field sensors (not shown) may be used in addition to the magnetic field sensors 812, 814 to improve signal processing (for example, to take into account magnetic noise such as near-field and far-field ambient magnetic fields that may be present in the output signals from each magnetic field sensor 812, 814).

[0104] Preferably, the transfer case housing 806 is made of a material such as aluminum that has low permeability with respect to the magnetic flux generated from the magnetically tuned region 810 when torque is applied to the power transmission shaft 804. The available space within the transfer case housing 806 may vary depending on the type and model of the vehicle, but should be large enough to accommodate the magnetic field sensors 812, 814 (and secondary sensors). The internal space of the transfer case housing 806 may be filled or partially filled with incompressible hydraulic oil.

[0105] As shown in the diagram, the small space surrounding the power transmission shaft 804 may be as small as about 10 mm, which is roughly sufficient for the operation of the magnetic field sensors 812, 814 and the secondary magnetic field sensor.

[0106] Referring to Figure 9, a schematic cross-sectional perspective view is shown thereof, illustrating another exemplary transfer case device 902 for a vehicle. This transfer case device 902 includes a portion of the power transmission shaft 904 within the transfer case housing 906.

[0107] Similar to the embodiments described above, the illustrated portion of the power transmission shaft 904 may be solid or partially hollow and may have a diameter D of approximately 30 mm. The shaft 904 may include a torque sensor 908 which is part of the power transmission shaft 904, and this portion of the power transmission shaft 904 is given a magnetically tuned region 910 which is integral to the portion of the shaft and extends circumferentially around the shaft and radially within the shaft for a distance from the surface forming a transducer portion of substantially uniform thickness d. The magnetically tuned region 910 may be fabricated in the portion of the power transmission shaft which is a ferromagnetic material including carbon steel, and may comprise one, two, three, or more alternating circumferentially polarized bands or regions (only three bands are shown in this example, and they are substantially circumferentially polarized in the directions roughly indicated by the arrows).

[0108] Corresponding non-contact magnetic field vector sensors 912-1, 912-2, ... 912-n (only two are shown) may be arranged circumferentially around one of the polarization bands or regions at various substantially equal azimuth angles in the same axial position (for example, a pair of two sensors arranged at a 180-degree azimuth angle). Similarly, non-contact magnetic field vector sensors 914-1, 914-2, ... 914-n (only two are shown) may be arranged circumferentially around one of the other polarization bands or regions at various substantially equal azimuth angles in a different axial position from magnetic field sensor 912. In the illustrated embodiment, a third set of non-contact magnetic field vector sensors 916-1, 916-2, ... 916-n (only two are shown) may be arranged circumferentially around one of the other polarization bands or regions at various substantially equal azimuth angles in a different axial position from magnetic field sensors 912 and 914.

[0109] The magnetic field sensors 912, 914, and 916 in each group are generally oriented in pairs such that an external magnetic flux is generated from the magnetically tuned region 910 by the torque applied to the power transmission shaft 904. These pairs of magnetic field sensors have sensing directions set to determine the rotational direction of the power transmission shaft 904 and the magnitude of the torque applied to the shaft. Additional secondary magnetic field sensors (not shown) may be used in addition to the magnetic field sensors 912, 914, and 916 to improve signal processing (for example, to take into account magnetic noise such as near-field and far-field ambient magnetic fields that may be present in the output signals from each magnetic field sensor 912, 914, and 916).

[0110] Preferably, as in the embodiments described above, the transfer case housing 906 is made of a material such as aluminum that has low permeability with respect to the magnetic flux generated from the magnetically tuned region 910 when torque is applied to the power transmission shaft 904. The available space within the transfer case housing 906 may vary depending on the type and model of the vehicle, but should be large enough to accommodate the magnetic field sensors 912, 914, 916 (and secondary sensors). The internal space of the transfer case housing 906 may be filled with or partially filled with incompressible hydraulic oil.

[0111] Referring to Figure 10, a schematic cross-sectional view of a torque sensor 1002 of a transmission drive plate 1004 for a vehicle (roughly indicated by a dashed box) is shown therein. As shown in the figure, the transmission drive plate 1004 may comprise magnetically tuned regions 1006 in the form of two radially extending annular magnetically polarized ring-shaped regions or ring-shaped bands 1006-1, 1006-2. The outward magnetically polarized region or outward magnetically polarized band 1006-1 comprises associated magnetic field vector sensor pairs 1008-1, 1008-4, and the inward magnetically polarized region or inward magnetically polarized band 1006-2 comprises associated magnetic field vector sensor pairs 1008-2, 1008-3. Together, each pair of sensors provides a measurement (magnitude and direction) of torque that can be applied by the transmission drive plate 1004 to, for example, a power transmission shaft 1010.

[0112] Referring to Figure 11, an alternative configuration of the apparatus in Figure 10 is shown therein. In this alternative configuration, the power transmission shaft 1010 extends along its longitudinal axis, so that a portion of the power transmission shaft 1010 (or a portion of the shaft) or the housing surrounding the power transmission shaft 1010 can be equipped with a torque sensor 1102, which may be given a magnetically tuned region 1104 having three axially extending circumferentially magnetically polarized regions or bands 1106, 1108, 1010 as described above. Each magnetically polarized region or magnetically polarized band 1104, 1106, 1108 is associated with a pair (or more pairs) of magnetic field vector sensors.

[0113] Corresponding non-contact magnetic field vector sensors 1112-1, 1112-2, ... 1112-n (only two are shown) can be arranged circumferentially around one of the polarization bands or regions at various substantially equal azimuth angles in the same axial position (for example, a pair of two sensors arranged at a 180-degree azimuth angle). Similarly, non-contact magnetic field vector sensors 1114-1, 1114-2, ... 1114-n (only two are shown) can be arranged circumferentially around another of the polarization bands or regions at different axial positions from magnetic field sensor 1112, and at various substantially equal azimuth angles. In the illustrated embodiment, a third set of non-contact magnetic field vector sensors 1116-1, 1116-2, ... 1116-n (only two are shown) may be arranged circumferentially around one of the other polarization regions or polarization bands, at different axial positions from magnetic field sensors 1112, 1114, and at various substantially equal azimuth angles.

[0114] The magnetic field sensors 1112, 1114, and 1116 in each group are generally oriented in pairs to detect the magnetic field generated when an external magnetic flux is generated from the magnetically tuned region 1104 due to the torque applied to the power transmission shaft 1010. These magnetic field sensor pairs have sensing directions set to determine the rotational direction of the power transmission shaft 1010 and the magnitude of the torque applied to the shaft. Additional secondary magnetic field sensors (not shown) may be used in addition to the magnetic field sensors 1112, 1114, and 1116 to improve signal processing (for example, to take into account magnetic noise such as near-field and far-field ambient magnetic fields that may be present in the output signals from each magnetic field sensor 1112, 1114, and 1116).

[0115] In each of the above configurations, the arrangement of the torque sensors and their components is shown schematically for the sake of clarity and illustration. Those skilled in the art will understand that, in order to achieve, among other design specifications and requirements, particularly sufficient detectable flux, magnetic field sensing and sensing accuracy, repeatability, and torque sensor service life, the magnetically tuned regions (transducers) and magnetic field vector sensors can be positioned and configured at various locations on the vehicle's powertrain.

[0116] In each of the above configurations, the shaft-type torque sensor and the disk-type torque sensor may be formed from a homogeneous material or from a mixture of materials. At least a portion of this material must be ferromagnetic enough to ensure the presence of magnetic domains to form at least residual magnetization in the magnetically tuned region. The material must be magnetostrictive such that the orientation of magnetic field lines above the magnetically tuned region or magnetically tuned band can be altered by a stress associated with the applied torque.

[0117] Both the shaft and the disc transducer may be completely solid or partially hollow. The diameter of the power transmission shaft may be, for example, about 30 mm. The thickness of the disc may be, for example, about 1 cm. The diameters of the left half-shaft and the right half-shaft may be changed depending on the specific vehicle type.

[0118] These magnetic field vector sensors are positioned near the magnetically tuned region at the location where the magnetic field strength is maximum. Each individual sensor is oriented so that its sensing direction is perpendicular to the magnetization direction in the magnetically tuned region. This configuration ensures that the signal output by each individual magnetic field sensor changes almost linearly with respect to fluctuations in the torque applied to the shaft or disk.

[0119] This arrangement of each pair of magnetic field sensors enables common-mode noise rejection. The output signals from each magnetic field sensor in each sensor pair are summed to produce a signal representing the torque applied to the shaft / disk. All external magnetic fields have an equal effect on each of the magnetic field sensors in this pair. Because the magnetic field sensors in this pair are polarized in opposite directions, the sum of their outputs is zero with respect to the external magnetic field. However, because the magnetically tuned region includes a region or band that is polarized in the opposite direction as well as each magnetic field sensor, the sum of the magnetic field sensor outputs becomes the derivative of each magnetic field sensor with respect to the torque applied to the shaft / disk. Thus, arranging the magnetic field sensors in a common-mode rejection configuration reduces the adverse effects of compassing on the output signal of the torque sensor device.

[0120] As described above, in some embodiments, the magnetically tuned region may comprise two, three, or more regions or bands that are polarized in opposite or alternating directions, with magnetic field lines set in nearly opposite circumferential directions. A pair of magnetic field sensors may be positioned near each of the regions or bands that cover the portion of the region or band where the magnetic field strength is maximum.

[0121] As described above, a magnetic field vector sensor for each region or band may comprise multiple individual magnetic field sensors, such as four sensors positioned at 90, 180, 270, and 360 degrees around the shaft. Each individual magnetic field sensor may be configured to correspond to a noise source (not shown) that generates a local magnetic field gradient having a different effect on each of the individual magnetic field sensors.

[0122] As discussed above, in a stationary state, the magnetic field in the magnetically tuned region is either zero (no external magnetic flux is generated) or arranged substantially only axially or substantially only circumferentially, depending on how the magnetically tuned region was initially formed. When torque is applied, the magnetic moments in the magnetically tuned region tend to tilt helically along the shear stress direction, which forms an angle of approximately 45 degrees with respect to the shaft surface, as described in more detail in the aforementioned references. Due to this tilt, the magnetization of the magnetically tuned region shows a decrease in component in the initial direction and an increase in component in the shear stress direction. The degree of tilt is proportional to the intensity of the applied torque. These magnetic field sensors are capable of sensing changes in the intensity of the magnetic field component along the sensing direction of the magnetic field sensor. Therefore, when torque is applied to the shaft / disk, the magnetic field sensor outputs a corresponding signal proportional to the applied torque.

[0123] Magnetic field sensors suitable for this application are commercially available from Methode Electronics, Inc. (Chicago) and include fluxgate inductors and Hall effect sensors. Preferably, the magnetic field sensor according to the present invention is a fluxgate inductor having a solenoid configuration.

[0124] software

[0125] Referring now to Figure 12, schematic diagrams are shown therein that illustrate some vehicle components monitored by one or more torque sensor devices ("sensing components") and software modules or computations ("algorithms") that are improved by input signal information from the torque sensor devices. Computation embodiments of the present invention include at least a signal processing circuit for receiving individual or combined magnetic field sensor signals from individual magnetic field sensors associated with the following, depending on a particular vehicle configuration:

[0126] (1) Torque sensors 316, 318, 320 associated with the rear differential device 302 (Figure 3A)

[0127] (2) Torque sensors 320 and 322 associated with the crown gear wheel 308 and the left rear half shaft shaft 312 (Figure 3B)

[0128] (3) Torque sensors 426, 430, and 440 associated with the rear differential device 402 and the right rear half-shaft shaft 414 (Figure 4)

[0129] (4) Torque sensors 512 and 514 associated with the half-shaft shaft device 502 (Figure 5)

[0130] (5) Torque sensors 612 and 614 associated with the half-shaft shaft device 602 (Figure 6)

[0131] (6) Torque sensors 712 and 714 associated with the half-shaft shaft device 702 (Figure 7)

[0132] (7) Torque sensor 808 associated with transfer case device 802 (Figure 8)

[0133] (8) Torque sensor 908 associated with transfer case device 902 (Figure 9)

[0134] (9) Torque sensor 1002 associated with transmission drive plate 1004

[0135] (10) Torque sensor 1102 associated with power transmission shaft 1010 (Figure 11)

[0136] Referring to Figure 13, a schematic diagram of some vehicle components of vehicle 1302 is shown therein. This vehicle 1302 comprises a transmission 103, a transfer case 104, a front power transmission drive shaft 105, a front differential 106, a left front half shaft shaft, a right front half shaft shaft, a rear power transmission drive shaft 304, a rear differential 322, a left rear half shaft shaft 312, and a right rear half shaft shaft 314 for front-wheel drive and / or rear-wheel drive vehicles (see Figures 1 and 3A). As schematically illustrated, one or more individual torque sensors 1304, 1306, 1308, 1310, 1312, 1314, 1316 (in addition to other torque sensors shown, e.g., in Figures 3B to 11, etc.) may be positioned approximately as illustrated to provide dynamic feedback during the operation of vehicle 1302. For example, each torque sensor may output its own signal T1304, T1306, T1308, T1310, T1312, T1314, T1316, which reflects the torque measured by the individual torque sensors 1304, 1306, 1308, 1310, 1312, 1314, and T1316.

[0137] Some vehicles may only require specific sensors in selected locations, meaning that not all of these torque sensors may be necessary in a particular vehicle. In some cases, where it is possible to rely on known relationships (e.g., efficiency) between components, sensors on both sides of the force transmission coupling may be unnecessary. Even in such cases, more torque sensors than necessary may be installed during manufacturing, as adding vehicle components later to accommodate additional sensors may be more expensive. In such cases, some torque sensors may be installed but not operational, however, these sensors can be made operational by electrical connection or simply by updating the firmware or software settings.

[0138] The signals from each torque sensor may be output from a local signal processing module associated with each torque sensor. These local modules can receive and process individual signals from each individual magnetic field vector sensor associated with each torque sensor.

[0139] One or more electronic control units 1318 (only one is shown) may be used to receive one or more of the individual output signals T1304, T1306, T1308, T1310, T1312, T1314, and T1316 in operation. Depending on the specific application, selected output signals may be used as inputs to specific algorithms as discussed above. Outputs from the algorithms may be transmitted from the electronic control units 1318 to an onboard computer 1320 installed in the vehicle 1302. This onboard computer 1320 may include engine management software to output control signals for controlling, for example, engine or motor power output.

[0140] The memory device 1322 may be associated with one or more electronic control units 1318 for storing tables, databases, and / or knowledge bases 1324 in memory, which can be uploaded to the memory device by the vehicle manufacturer, vehicle owner or operator, or any other party, either via a wired connection or a wireless connection using a transceiver (not shown). The stored information may include one or more numerical values, functions (step-up functions, amplification functions, ramp functions, or others), criteria (high / low ranges, maximum values, low values, intensity, or others), calibration curves (slope-intercept values, etc.), input / output pairs or decision pairs (i.e., do this in this case, do that otherwise), machine learning models (classification, etc.), state sets or situation sets (S), and action sets (A) associated with a state (i.e., for each S in a set, A is S i This includes other stored information used to evaluate certain vehicle characteristics, adjust entry signals, or evaluate the actions to be taken, such as historical logs, other algorithms, or one or more algorithms stored in a memory device, as input to these algorithms.

[0141] The state may be, or reflect, position, setting, flow rate, linear velocity, rotational velocity, acceleration, output state, current, sound frequency, sound level, vibration frequency, fluid fill level, opacity, temperature, pressure, concentration, material selection, brightness, output, data storage, or other physical or chemical state associated with a stationary or operating vehicle.

[0142] As a non-limiting example, given a vehicle characteristic state S0 at time t0 and a set of possible actions A associated with that state, a particular algorithm may identify the next possible action A1 or A2 to be taken within the memory device 1322. However, if torque signals T1314 and T1316 are acquired at time t1 from torque sensors 1314 and 1316 reflecting the torque on the left rear half-shaft axis and the right rear half-shaft axis, respectively (which may suggest wheel slip in combination with other sensors), the algorithm may identify action A3 as the next action to be taken, as follows.

[0143] A(S t0 |T t0 )=A1 or A2 (11)

[0144] A(S t1 |T1314 t1 , T1316 t1 )=A3 (12)

[0145] Each torque sensor may be provided with leads or cables leading to a connector for linking with a printed circuit board in the electronic control unit 1318, which may be a connector for linking with the onboard computer 1320 of the vehicle 1302. Logic circuits for each of the applications described below may be implemented on one or more printed circuit boards, which may be located within one or more modules of the electronic control unit 1318, each having its own input / output connectors, power supply, and housing as needed.

[0146] Purpose

[0147] As a non-limiting example, torque information from torque sensor devices as described above can be useful in determining vehicle weight. Furthermore, torque information can be useful in predictive maintenance (detecting problems before catastrophic failure), for condition monitoring (for example, when using chip tuning and applying overtorque exceeding the transmission's torque rating), and for detecting wheel slip during acceleration and braking (although even in this use case, an appropriate sensor would be placed between the brake and the wheel in contact with the road).

[0148] In the example of vehicle weight, the dynamic vehicle weight calculation involves at least the following input parameters, some of which may be predetermined or fixed values, while others may be measured directly using torque sensor devices and other sensors as described herein.

[0149] (1) Engine horsepower

[0150] (2) Torque (measured at the output of the engine, each wheel, and power transmission shaft)

[0151] (3) Speed ​​(rpm), engine

[0152] (4) Velocity and acceleration

[0153] (5) Fixed size or fixed mass (wheels, shafts, chassis, other components)

[0154] (6) Gear ratio (transfer case, differential)

[0155] (7) Correction factors (considering efficiency / loss, temperature, humidity, traction force and rolling resistance, and additional loads)

[0156] Among other configurations and uses, the torque sensor devices of the types described above may be used to provide information to assist in measuring the torque of a vehicle's powertrain, including, for example, measurements from sensors mounted in mounting holes in housings used for powertrain components. In one embodiment, a torque sensor device may be used to measure the amount of torque applied to a transmission sprocket disc in a housing.

[0157] In alternative configurations and uses, the torque sensor devices of the types described above may be used inside a rotating shaft and / or in conjunction with a planetary gear set within a housing. In one embodiment, space for a torque sensor device (or multiple such devices) may be provided by modifying a conventional housing, such as by extending a portion of the main housing to form a cavity with sufficient capacity to accommodate a magnetic field vector sensor. If necessary, a transmission shaft extending through a cavity formed by the housing may be modified, such as by extending the housing to form a magnetorheologically active region on the shaft itself.

[0158] In yet another configuration and use, the torque sensor devices of the types described above may be used to regulate the operation of powertrain components to achieve a desired driveline torque by monitoring the actual driveline torque, and this regulation may include regulating the operation of the driveline disengagement clutch. System-level signals from one or more torque sensors may be used as feedback to the driveline disengagement actuator to correct operational errors of the disengagement clutch and achieve the desired torque.

[0159] In alternative configurations and uses, mass calculations may be performed to determine the total effective center of mass weight of the vehicle, taking into account the vehicle, occupants, cargo or other material carried by the vehicle, mounted towing capacity, additional components, and other mass-supporting items. This calculation may be performed using a variety of inputs, including the inertia of the rotating components, acceleration (calculated or measured using an accelerometer), velocity (calculated or measured), torque / force at the drive wheels, resistance to motion (i.e., ground friction, wind resistance), total torque ratio, power transmission efficiency, geometry of the rotating components, tire pressure, temperature, and others. Each input may be calculated in real time during vehicle operation. Some inputs may be fixed and correlated, and therefore provided by lookup tables when certain inputs are known (i.e., calibration "curves" such as linear equations that take certain inputs and provide correlated outputs).

[0160] In yet another configuration and use, the types of torque sensor devices described above may be used to improve shifting in transmission components by accurately detecting the onset of a torque phase shift. This can be done by indirectly measuring the input torque at the transmission input shaft, specifically by monitoring the initial rise in the output signal representing the torque measurement at the transmission input shaft.

[0161] In alternative configurations and uses, the types of torque sensor devices described above may be used to provide feedback to direct-measuring torque sensor systems used in dual-clutch automatic transmissions. In dual-clutch automatic transmissions where torque is directly measured at the drive plates of the dual-clutch transmission, useful monitoring information can be obtained to assist in improving clutch control and power transmission from the engine to the drive wheels. Information about the condition of the drive wheels, such as slip, can further improve the automatic transmission function. Therefore, torque sensor devices may be positioned on the differential input shaft and on each of the half-shafts extending from the differential to the drive wheels to improve the performance of the dual-clutch automatic transmission by providing feedback (input) to the automatic transmission sensor algorithm. Furthermore, additional torque sensor devices of the types described above used between the brakes and wheels may be used to provide additional information to the clutch controller and engine power management controller.

[0162] In yet another configuration and use, the torque sensor devices of the types described above may be further used to provide feedback (input) to a sensor system used for monitoring friction elements of an automatic transmission for the purpose of controlling the upshift and downshift of the transmission. Such a sensor system may provide information on the input torque and input velocity of the transmission input shaft, information on the output torque and output velocity of the output shaft from the transmission, and information on the vehicle speed and throttle position. One or more of these torque sensor devices may be positioned on the differential input shaft and on each of the half shafts extending from the differential to the drive wheels to provide the necessary feedback (input) to the upshift and downshift algorithms.

[0163] In yet another configuration and use, the types of torque sensor devices described above may be further used to improve the calculation of torque in moving friction elements (i.e., by comparing this torque with a predetermined target torque value), which is useful in controlling non-moving friction elements in a multi-ratio transmission mechanism. Typically, for this purpose, torque sensors are placed on one or both of the transmission torque input shaft and the transmission torque output shaft. However, the additional torque sensor devices of the type described herein may be added to the differential input shaft and to each of the half-shafts extending from the differential to the drive wheels to better estimate the output torque of the transmission mechanism by providing additional feedback. These additional torque sensor devices help improve the accuracy of the estimation of the torque experienced by friction elements in the transmission during a shift event compared to estimations that rely solely on the transmission shaft input torque and transmission shaft output torque.

[0164] Furthermore, if torque measurement is impossible at critical locations, the controller must rely on estimated torque values ​​obtained from the torque profile, which themselves are determined from other monitoring parameters associated with the vehicle and may therefore be less accurate than direct measurements. The need to rely on the torque profile can be reduced by adding one or more torque sensor devices of the types described above to the differential input shaft and to each of the half-shafts extending from the differential to the drive wheels.

[0165] In yet another configuration and use, by adding the aforementioned types of torque sensor devices to the differential input shaft and to each of the half-shafts extending from the differential to the drive wheels, additional input data can be provided to algorithms for estimating noise, vibration, and harshness levels in powertrain components.

[0166] Furthermore, by adding one or more torque sensor devices of the aforementioned types to the differential input shaft and to each of the half shafts extending from the differential to the drive wheels, the necessary information can be provided for use in further improved control of manual transmission gear shifts, specifically to provide input to a controller that determines the clutch torque transmitted via the input clutch associated with the desired gear after the shift lever has been manually moved.

[0167] In yet another configuration and use, adding the aforementioned types of torque sensor devices to the differential input shaft and to each of the half-shafts extending from the differential to the drive wheels can provide additional input data to an algorithm for estimating the amount of backlash in the torsional discontinuity during a change in torque direction. The torsional discontinuity may exist between the drive pinion gear mounted on the transmission shaft, the crown wheel gear mounted on one half-shaft, and the bevel gear mounted on the other half-shaft, all of which are located inside the rear or front differential housing. This torsional discontinuity appears when the contact between gear teeth changes (i.e., non-contact or low-contact) due to a decrease or change in direction of the input torque transmitted by individual gear tooth surfaces that are in contact with other gear tooth surfaces. By using the torque sensor on all three of the above shafts, the detection of this transition backlash period is improved, allowing for feedback to be provided to the appropriate transmission and / or motor controller, and further enabling the use of this information to improve drivability.

[0168] In yet another use, by adding the aforementioned types of torque sensor devices to the differential input shaft and to each of the half-shafts extending from the differential to the vehicle's drive wheels, additional input data can be provided to algorithms for controlling the power output of the vehicle engine to adjust the distance to another vehicle during automatic or semi-automatic operation. In automatic or semi-automatic mode, the controller can adjust engine power to maintain a predetermined or driver-inputted distance. Power may be adjusted using information about the actual distance, vehicle mass, road gradient, and other parameters. Some of these parameters may be calculated from an estimate of the force exerted by the wheels on the road surface, which may be indirectly estimated by measuring or acquiring information about tire diameter, engine torque output, transmission gear, transmission drive ratio, and other parameters. However, the sensor allows for a more direct measurement of the force exerted by the wheels on the road surface and therefore a more accurate determination of the amount of engine power output required to maintain a particular distance.

[0169] In another use, the outputs from the two types of half-shaft torque sensors described above, along with the outputs from torque sensor devices located between the brake and the wheel, may be useful as inputs to a controller used to control the individual wheel speeds of wheels mounted on a shared differential by applying individually selective braking pressure amounts to each wheel. This can be useful, for example, when an anti-lock braking system (ABS) is activated and one of the shared wheels slides (stops) on the road surface for a short period instead of continuing to rotate, while the other wheels continue to rotate. The arrangement of these torque sensors as described above can improve the reduction of vibrations that may occur when the ABS system systematically adjusts the braking pressure under such conditions.

[0170] In yet another use, one or more torque sensor devices of the types described above, including torque sensor devices located on the differential input shaft and on each of the half-shafts extending from the differential to the vehicle's drive wheels, may provide additional input data to a cruise control algorithm to precisely control engine power output and maintain the distance between vehicles on the road.

[0171] In another use, the output from one or more torque sensor devices of the types described above may provide data that suggests an anomaly in vehicle operating characteristics requiring maintenance when compared to a predetermined criterion. An event may be recorded in a memory device, along with relevant data for diagnostic purposes, if the torque amount directly measured (or calculated from indirect measurements) during a shift event of an automatic transmission component falls outside a predetermined range or exceeds or falls below a specific limit. Visual and / or audible alerts may be provided to the operator to suggest that maintenance may be required. The torque amount being measured may be associated with, for example, torque applied or transmitted by a gear or gear shifting component, power transmission shaft, drive wheel axle or half-axle, brake, or other component. The comparison criterion may be associated with a model of the above and other or multiple components and may be determined during the design phase of the component / assembly or from testing after the final component / assembly. This criterion may be stored in the memory device in the form of a linear or nonlinear relationship between parameters, between specific high / low values, or between specific tolerance ranges.

[0172] In yet another use, torque sensor devices of the type described above, located on the differential input shaft and on each of the half-shafts extending from the differential to the vehicle's drive wheels, may provide additional input data to an algorithm for regulating the hydraulic pressure used to engage the clutch in the gearbox. Typically, hydraulic pressure can be regulated by opening and closing (or partially opening and closing) a valve and / or by changing the flow output from a hydraulic pump that allows the space to be filled with hydraulic fluid. This valve and / or pump may be controlled by a hydraulic control system, taking into account the configuration of specific clutch and gearset elements between the input and output, using in part direct measurements of the driver-requested torque at the transmission input and direct measurements at the output (drive shaft). However, by using the additional input data described above, the output torque amount directly measured at the transmission output shaft can be improved, and therefore the regulation of hydraulic pressure (and thus the operation of the clutch components) can be improved. The input data may also reflect information regarding immediate torque measurements, the rate of change in the torque measurements, and / or the percentage variation (standard deviation) from the net (central) actual value measured over a period of time, obtained by one or all of the additional torque sensor devices, and this information may be fed back to the appropriate valve / pump controller module.

[0173] In another application, torque sensor devices of the type described above, located on the differential input shaft and on each of the half-shafts extending from the differential to the vehicle's drive wheels, may provide additional input data to an algorithm used to control the vehicle's launch from a standing start when the vehicle is using "Launch Control" mode or "Track" mode. Launch control requires accurate power measurements at all drive wheels and during the sudden start of power output from the engine or motor, which is achieved by the additional torque sensor devices described above. In this case, the calculated vehicle characteristics may be wheel rotation speeds, and the vehicle's current state may be the power output request from the vehicle's engine or motor, indicated by the throttle pedal position.

[0174] In yet another use, the calculated vehicle characteristics may be fuel efficiency, and the current state of the vehicle may be intake valve position and fuel pump settings. The types of torque sensor devices described above may also be used to provide information on fuel efficiency calculated at a particular point in time or period, and combined with information on available intake valve position and fuel pump flow rate settings, a signal may be generated to change the valve position and / or fuel flow rate to improve fuel efficiency.

[0175] One advantage of using torque sensors in the manner described above and in other applications is that it is possible to obtain useful information about vehicle characteristics immediately before applying force to the vehicle's components. In more conventional approaches, sensors are placed to evaluate conditions or states after a force has been applied, but such feedback loops can create undesirable conditions. For example, identifying the torque split between the left and right half-shaft axes in a differential can be useful in predicting the possibility of wheel slip, whereas sensors associated with an automatic braking system (ABS) can only detect wheel slip after hazardous conditions have occurred and become measurable by the ABS sensor.

[0176] While this specification has specifically described several currently preferred embodiments of the invention disclosed herein, it will be apparent to those skilled in the art that various modifications and alterations of the embodiments illustrated and described herein can be made without departing from the spirit and scope of the invention. Accordingly, the invention is intended to be limited only to the scope required by the appended claims and applicable laws. [Explanation of symbols]

[0177] 2. Shaft-type torque sensor device 4 transducers 6. Magnetic field vector sensor 8. Circumferential polarization region, magnetically tuned region, magnetically tuned band. 10 Circumferential polarization region, magnetically tuned region, magnetically tuned band 11 axes 12 shafts 20 Torque 24 Electrical Wires 102 Differential Components 103 Transmission 104 Transfer Case 105 Front power transmission drive shaft 106 Front Differential 107 Rear power transmission drive shaft 108 Rear Differential 110 discs 140 Magnetoelastic active region 142 Magnetically adjusted area 144 Magnetically adjusted areas 152 Magnetic field sensor 154 Magnetic field sensor 302 Rear Differential Device 304 Power transmission shaft 306 Drive Pinion Gear 308 Crown Gear Wheel 309 Gear section 310 Bevel Gear 312 Left rear half shaft axis 314 Right rear half shaft axis 316 Shaft-type primary side non-contact torque sensor 316-1 Magnetic field sensor 316-2 Magnetic field sensor 316-3 Magnetic field sensor 316-4 Magnetic field sensor 318 Primary side non-contact torque sensor 320 Primary side non-contact torque sensor 320-1 Magnetic field sensor 320-2 Magnetic field sensor 320-3 Magnetic field sensor 320-4 Magnetic field sensor 322 Differential housing, disc type primary non-contact torque sensor, rear differential 322-1 Magnetic field sensor 322-2 Magnetic field sensor 322-3 Magnetic field sensor 322-4 Magnetic field sensor 340 Magnetoelastic active region 342 Magnetically regulated areas, magnetically regulated bands 344 Magnetically tuned areas, magnetically tuned bands 402 Rear Differential Device 404 Power transmission shaft 406 Drive Pinion Gear 408 Crown Gear Wheel 410 Bevel Gear 414 Right rear half shaft axis 416 Wheel hub connecting end 418 Shaft 420 Rear differential connecting end 422 Internal constant velocity joint 424 Outer constant velocity joint 426 Torque sensors, magnetic field sensors 426-1 Magnetic field sensor 426-2 Magnetic field sensor 430 Torque Sensor 440 Magnetically Adjusted Areas 440-n Non-contact Magnetic Field Vector Sensor 502 Half-shaft axis device 504 Wheel hub connecting section 506 Outer CV joint or other types of joints 508 shaft 510 Differential coupling section 512 Torque Sensor 512-n Non-contact magnetic field vector sensor 514 Torque Sensor 514-n Non-contact magnetic field vector sensor 602 Half-shaft axis device 604 Wheel hub connecting end 606 Outer CV type or other types of joints 608 Shaft 610 Differential coupling section 612 Torque Sensor 612-n Non-contact magnetic field vector sensor 614 Torque Sensor 614-n Non-contact magnetic field vector sensor 616 Inner CV type or other types of joints 702 Half-shaft axis device 704 Wheel hub connecting end 706 Outer CV joint or other types of joints 708 Shaft 710 Differential coupling section 712 Torque recovery 712-n Non-contact magnetic field vector sensor 714 Torque Sensor 714-n Non-contact magnetic field vector sensor 716 U-joint 802 Transfer Case Device 804 Power transmission shaft 806 Transfer Case Housing 808 Torque Sensor 810 Magnetically adjusted area 812 Magnetic field sensor 812-n Non-contact magnetic field vector sensor 814 Magnetic field sensor 814-n Non-contact magnetic field vector sensor 902 Transfer Case Device 904 Power transmission shaft 906 Transfer Case Housing 908 Torque Sensor 910 Magnetically regulated area 912 Magnetic field sensor 912-n Non-contact magnetic field vector sensor 914 Magnetic field sensor 914-n Non-contact magnetic field vector sensor 916 Magnetic field sensor 916 Non-contact magnetic field vector sensor 1002 Torque Sensor 1004 Transmission Drive Plate 1006 Magnetically adjusted area 1006-1 Outer magnetic polarization region or outer magnetic polarization band 1006-2 Outer magnetic polarization region or outer magnetic polarization band 1008-1 Magnetic field vector sensor 1008-2 Magnetic field vector sensor 1008-3 Magnetic field vector sensor 1008-4 Magnetic field vector sensor 1010 Power transmission shaft 1102 Torque Sensor 1104 Magnetically tuned region, magnetically polarized region, magnetically polarized band 1106 Magnetic polarization region, magnetic polarization band 1108 Magnetic polarization region, magnetic polarization band 1112 Magnetic field sensor 1112-n Non-contact magnetic field vector sensor 1114 Magnetic field sensor 1114-n Non-contact magnetic field vector sensor 1116 Magnetic field sensor 1116-n Non-contact magnetic field vector sensor 1302 Vehicles 1304 Torque Sensor 1306 Torque Sensor 1308 Torque Sensor 1310 Torque Sensor 1312 Torque Sensor 1314 Torque Sensor 1316 Torque Sensor 1318 Electronic control unit 1320-equipped computer 1322 memory devices 1324 Knowledge Base

Claims

1. A system for dynamically evaluating vehicle characteristics, Power transmission shaft torque sensor, or left rear half shaft torque sensor and right rear half shaft torque sensor, At least one electronic control unit configured to receive either an electronic signal from the power transmission shaft torque sensor representing a torque measurement of the power transmission shaft, or electronic signals from the left rear half shaft shaft torque sensor and the right rear half shaft shaft torque sensor, respectively, representing torque measurements of the left rear half shaft shaft and the right rear half shaft shaft, respectively; calculate the vehicle characteristics based on the received electronic signals; and output an output signal for use in changing the current state of the operating vehicle based on the calculated vehicle characteristics; Equipped with, Each of the aforementioned torque sensors A magnetically adjusted region extending axially and integrally with each portion of the shaft is formed around the shaft in the circumferential direction and within the shaft by a distance from the surface of the shaft in the radial direction, At least two non-contact magnetic field vector sensors located near each of the magnetically adjusted regions, each having a sensing direction configured to determine the rotation direction of the shaft by detecting the magnetic flux extending from each surface of the magnetically adjusted region, Equipped with, The magnetically tuned region comprises two or more axially extending and circumferentially magnetically polarized bands or regions, wherein adjacent bands or regions are alternately magnetically polarized in the circumferential direction. The power transmission shaft torque sensor is located at the differential end of the shaft, and the left rear half shaft torque sensor and the right rear half shaft torque sensor are located at the differential ends of the half shafts, respectively. system.

2. The system according to claim 1, wherein the electronic signal from the torque sensor represents the torque measurement value of the power transmission shaft at the differential end, and the electronic signals from the left rear half shaft torque sensor and the right rear half shaft torque sensor each represent the torque measurement values ​​of the left rear half shaft and the right rear half shaft at the differential end.

3. The system according to claim 1, further comprising a memory device for storing one or more algorithms and information relating to a plurality of different vehicle operations, calibrations, or functions corresponding to the vehicle characteristics, wherein at least some of the calculated vehicle characteristics correspond to one or more of the algorithms and information.

4. The system according to claim 3, wherein the one or more signal processing modules are further configured to calculate the vehicle characteristics and output an output signal for use in changing the current state of the operating vehicle based on the calculated vehicle characteristics and the plurality of different vehicle operations.

5. The system according to claim 1, wherein the at least one electronic control unit houses one or more signal processing modules comprising algorithms and information for calculating vehicle weight, predicting when maintenance should be performed, calculating the conditions of the vehicle, calculating wheel slip, calculating differential backlash, calculating noise, vibration, and harshness values, evaluating when an upshift or downshift should be performed, controlling the vehicle's starting operation from a standstill, calculating when clutch components should operate, managing the power output of the engine or motor, calculating when automatic braking system components should be changed, calculating fuel efficiency, and controlling the operation of the vehicle's hydraulic system.

6. A system for dynamically evaluating vehicle characteristics, A torque sensor associated with the power transmission shaft of a transfer case, which outputs an electronic signal representing a torque measurement of the power transmission shaft under the current state conditions of the vehicle, A portion of the power transmission shaft is integral with the aforementioned shaft and is given a magnetically tuned region that extends circumferentially around the shaft and radially into the shaft by a certain distance from the surface of the shaft, At least two non-contact magnetic field vector sensors located near the magnetically adjusted region, each having a sensing direction configured to determine the rotational direction of the power transmission shaft by detecting the magnetic flux extending from the surface of the magnetically adjusted region, A torque sensor equipped with, At least one electronic control unit configured to house one or more signal processing modules for receiving the electronic signal from the power transmission shaft torque sensor, calculating the vehicle characteristics based on the received electronic signal, and outputting an output signal for changing the state of the operating vehicle based on the calculated vehicle characteristics, Equipped with, The magnetically tuned region comprises two or more axially extending and circumferentially magnetically polarized bands or regions, wherein adjacent bands or regions are alternately magnetically polarized in the circumferential direction. The torque sensor is positioned at the differential end of the power transmission shaft. system.

7. The system according to claim 6, wherein two non-contact magnetic field vector sensors are positioned in the same axial position in one of the polarization bands or polarization regions and spaced circumferentially by an azimuth angle of about 180 degrees, and two non-contact magnetic field vector sensors are positioned in the same axial position in one of the other polarization bands or polarization regions and spaced circumferentially by an azimuth angle of about 180 degrees.

8. The system according to claim 6, further comprising one or more secondary magnetic field sensors for outputting a signal reflecting magnetic noise from one or more near-field or far-field magnetic fields.

9. The system according to claim 6, further comprising a transfer case housing that encloses at least a portion of the power transmission shaft, wherein the transfer case housing is made of a material having low permeability with respect to magnetic flux generated from the magnetically tuned region when torque is applied to the power transmission shaft.

10. A torque sensor integrated with a portion of the transfer case housing at the position where the housing is connected to the transmission, the torque sensor outputting an electronic signal representing a torque measurement at the position where the transfer case housing and the transmission are connected. The system according to claim 9, further comprising:

11. A disc-type torque sensor, which is integrated with a portion of the transfer case housing, wherein the transfer case housing is coupled to the housing of the transmission to output an electronic signal representing a torque measurement at the position where the transfer case housing and the housing of the transmission are coupled. The system according to claim 10, further comprising:

12. The system according to claim 10 or 11, wherein the at least one electronic control unit is further configured to house one or more signal processing modules for receiving the electronic signal from the power transmission shaft torque sensor located in the transfer case housing and the electronic signal from the power transmission shaft torque sensor located at the differential end representing a torque measurement of the power transmission shaft, calculating the vehicle characteristics based on the received electronic signals, and outputting an output signal for use in changing the current state of the operating vehicle based on the calculated vehicle characteristics.

13. A method for evaluating vehicle characteristics, In the electronic control unit, the steps include receiving an electronic signal representing the torque measurement value of the power transmission shaft from the power transmission shaft torque sensor, or receiving electronic signals representing the torque measurement values ​​of the left rear half shaft and the right rear half shaft respectively from the left rear half shaft torque sensor and the right rear half shaft torque sensor, A step of calculating the vehicle characteristics based on the received electronic signals using one or more signal processing modules in the electronic control unit, The steps include outputting an output signal for use in changing the current state of a vehicle in operation, based on the calculated vehicle characteristics, Includes, Each of the aforementioned torque sensors A magnetically adjusted region extending axially and integrally with each portion of the shaft is formed around the shaft in the circumferential direction and within the shaft by a distance from the surface of the shaft in the radial direction, At least two non-contact magnetic field vector sensors located near each of the magnetically adjusted regions, each having a sensing direction configured to determine the rotation direction of the shaft by detecting the magnetic flux extending from each surface of the magnetically adjusted region, Equipped with The magnetically tuned region comprises two or more axially extending and circumferentially magnetically polarized bands or regions, wherein adjacent bands or regions are alternately magnetically polarized in the circumferential direction. The power transmission shaft torque sensor is located at the differential end of the shaft, and the left rear half shaft torque sensor and the right rear half shaft torque sensor are located at the differential ends of the half shafts, respectively. method.

14. The method according to claim 13, wherein the power transmission shaft torque sensor is located at the differential end of the shaft, the electronic signal from the torque sensor represents the torque measurement value of the power transmission shaft at the differential end, and the left rear half shaft shaft torque sensor and the right rear half shaft shaft torque sensor are located at the differential end of the shaft, respectively, and the electronic signals from the left rear half shaft shaft torque sensor and the right rear half shaft shaft torque sensor each represent the torque measurement value of the left rear half shaft shaft and the right rear half shaft shaft at the differential end.

15. The method according to claim 13, further comprising the step of outputting an output signal for use in changing the current state of the operating vehicle, based on the calculated vehicle characteristics and a plurality of different vehicle operations stored in a memory device, wherein at least some of the calculated vehicle characteristics correspond to one or more of the stored vehicle operations.

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