Patent Publication Number: US-8989956-B2

Title: System, method and apparatus for real-time measurement of vehicle performance

Description:
BACKGROUND 
     Automotive enthusiasts frequently install modifications on their vehicles that enhance the performance of the vehicle&#39;s drivetrain. Such performance modifications can include intake manifolds allowing for less restricted airflow, modified exhaust headers, less restricted post-catalytic-converter exhaust systems, modified camshafts, ram-air intakes, cylinder head modifications, and so forth, as well as modifications to other systems of the vehicle. To conclusively determine the effects of a particular modification, it is necessary to measure the performance characteristics of the vehicle. In other instances, an owner may also wish to measure the performance characteristics of an unmodified vehicle. Typically, such measurements are performed on a dynamometer. Due to the significant cost and space requirements of dynamometers, an owner would need to take the vehicle to an automotive garage or shop. 
     Dynamometers typically fall into two categories: engine dynamometers and chassis dynamometers. An engine dynamometer requires that the motor be removed from the vehicle and attached to the apparatus. The engine is then accelerated with an opposing load provided by a controllable electrical or mechanical system, or a combination of the two. The acceleration is then correlated with the load and the motor torque can then be determined. If the engine shaft speed is known, the power rating of the motor can be calculated. The chassis dynamometer does not require that the engine be removed. In this case, the vehicle is placed on the dynamometer such that the drive wheels engage a roller, and an opposing load is then accelerated by the drive wheels. Based on the acceleration, load, and drive speed, the torque and power can be determined. 
     Both of the previously described methods present limitations, do not reflect real-world driving conditions, and are typically expensive. Removing the engine from the vehicle to use an engine dynamometer is labor-intensive, while the power losses due to the other drivetrain components are not known. A chassis dynamometer requires a qualified individual to secure the vehicle for safety, and does not account for losses due to the road surface nor the effects of actual driving conditions (such as, for example the effects of ram-air intakes). Both of the traditional methods are usually expensive and do not reflect real world driving. Furthermore, vehicle analysis systems used by original equipment manufacturers (OEMs) can be prohibitively expensive for individual or occasional use. A simple and inexpensive way of measuring vehicle performance characteristics in real-time while taking into account real-world driving conditions is therefore desired. 
     SUMMARY 
     According to at least one exemplary embodiment, system for real-time measurement of vehicle performance is disclosed. The system can include at least one sensor module mounted on a rotating member of the vehicle and a central module disposed in the vehicle. The sensor module can include a plurality of sensors communicatively coupled to a microcontroller, at least one wireless communications device communicatively coupled to the microcontroller, and a power source. The central module can include a central processor, memory, a central wireless communications device communicatively coupled to the central processor and to the at least one wireless communications device of the sensor module. The rotating member of the vehicle can be a wheel, a brake rotor, or a torsion disc disposed between an axle of the vehicle and a wheel of the vehicle. 
     According to another exemplary embodiment, a method for real-time measurement of vehicle performance is disclosed. The method can include providing a sensor module on a rotating member of the vehicle, providing a central module in the vehicle, receiving first measurement data from a plurality of sensors of the sensor module, receiving second measurement data from a data bus of the vehicle, and processing the first measurement data and the second measurement data to obtain calculated data for real-time horsepower and torque values at the rotating member. 
     According to another exemplary embodiment, a rotating member for a vehicle is disclosed. The rotating member of a vehicle can include a plurality of sensors disposed on the surface of the rotating member at locations that experience increased deflection relative to other locations on the surface of the rotating member, a microcontroller communicatively coupled to the plurality of sensors, at least one wireless communications device communicatively coupled to the microcontroller, and a power source. The rotating member may be a wheel, a brake rotor, or a torsion disc disposed between an axle of the vehicle and a wheel of the vehicle. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Advantages of embodiments of the present invention will be apparent from the following detailed description of the exemplary embodiments. The following detailed description should be considered in conjunction with the accompanying figures in which: 
         FIG. 1   a  shows an exemplary embodiment of a system for real-time measurement of vehicle performance installed in a vehicle. 
         FIG. 1   b  is a diagram of an exemplary embodiment of a central module for a system for real-time measurement of vehicle performance. 
         FIG. 1   c  is a diagram of an exemplary embodiment of a sensor module for a system for real-time measurement of vehicle performance. 
         FIGS. 2   a - 2   b  show an exemplary embodiment of a rotating member for a system for real-time measurement of vehicle performance. 
         FIGS. 3   a - 3   c  show another exemplary embodiment of a rotating member for a system for real-time measurement of vehicle performance. 
         FIGS. 4   a - 4   b  show another exemplary embodiment of a rotating member for a system for real-time measurement of vehicle performance. 
         FIG. 5  shows an exemplary embodiment of a method for real-time measurement of vehicle performance. 
     
    
    
     DETAILED DESCRIPTION 
     Aspects of the invention are disclosed in the following description and related drawings directed to specific embodiments of the invention. Alternate embodiments may be devised without departing from the spirit or the scope of the invention. Additionally, well-known elements of exemplary embodiments of the invention will not be described in detail or will be omitted so as not to obscure the relevant details of the invention. Further, to facilitate an understanding of the description discussion of several terms used herein follows. 
     As used herein, the word “exemplary” means “serving as an example, instance or illustration.” The embodiments described herein are not limiting, but rather are exemplary only. It should be understood that the described embodiment are not necessarily to be construed as preferred or advantageous over other embodiments. Moreover, the terms “embodiments of the invention”, “embodiments” or “invention” do not require that all embodiments of the invention include the discussed feature, advantage or mode of operation. 
     Further, many of the embodiments described herein are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It should be recognized by those skilled in the art that the various sequence of actions described herein can be performed by specific circuits (e.g., application specific integrated circuits (ASICs)) and/or by program instructions executed by at least one processor. Additionally, the sequence of actions described herein can be embodied entirely within any form of computer-readable storage medium such that execution of the sequence of actions enables the processor to perform the functionality described herein. Thus, the various aspects of the present invention may be embodied in a number of different forms, all of which have been contemplated to be within the scope of the claimed subject matter. In addition, for each of the embodiments described herein, the corresponding form of any such embodiments may be described herein as, for example, “a computer configured to” perform the described action. 
     Referring to  FIGS. 1   a - 1   c , in one exemplary embodiment, a system for real-time measurement of vehicle performance  100  is disclosed. System  100  may include a plurality of sensor modules  102  communicatively coupled to a central module  104 . System  100  may further include a data logger  106 , communications port  108 , and display  110 . Sensor modules  102  may be disposed on one or more rotating members of the vehicle, as described further below. Central module  104  may be mounted in any desired location of the vehicle, for example in the trunk, in the interior, under a seat, or behind the dashboard. As central module  104  may be adapted to communicatively couple with one or more of vehicle&#39;s data buses, the module may be mounted in a location that allows for easy coupling to the desired data buses. Some exemplary embodiments of central module  104  may provide for user interaction and can thus be mounted in a user-accessible location, for example on the dashboard or central console of the vehicle. Power to central module  104  may be provided by the electrical system of the vehicle. 
     Central module  104  may include a central processor  112 , memory  114 , and at least one communication coupling  116 . Memory  114  may be any known volatile or non-volatile information storage medium that enables system  100  to function as described herein, for example SRAM, DRAM, flash memory, and the like. Communication couplings  116  may include couplings for the vehicle&#39;s data buses. Central module  104  may be adapted to communicate utilizing standardized data bus protocols, for example OBD-II, CAN, VAN, MOST, LIN, D2B, KWP2000, FlexRay, or any other known standardized bus protocol. System  100  may further be adapted to communicate utilizing automobile manufacturers&#39; proprietary data bus protocols. As an illustrative example, in a BMW vehicle, such bus protocols may be the I-Bus, K-Bus and D-Bus. Any analogous automobile manufacturers&#39; proprietary data buses that enable system  100  to function as described herein may also be utilized. A communications coupling  116  may be provided for each desired data bus with which central module  104  may communicate. On older vehicles without data buses, the communications couplings may be adapted to tap into existing vehicle sensor outputs, with analog-to-digital converters provided as needed. Furthermore, desired sensors may be installed on such older vehicles, or any vehicles lacking desired sensors. 
     In addition to data received from sensor modules  102 , central module  104  may utilize data received from the vehicle data buses to which the central module is coupled. As an illustrative example, such data can include powertrain-related data such as engine speed, coolant temperature, oil pressure, mass airflow sensor readings, manifold pressure readings, spark timing, fuel supply data, knock sensor readings, oxygen sensor readings, or any other desired data. Furthermore, such data can include data from other vehicle systems, such as vehicle speed, brake application forces, anti-lock brake system data, stability and traction control data, steering angle, suspension-related information, or any other desired data. In some embodiments, central module  104  may further send data over the vehicle data buses. For example, in some embodiments, audio or video data may be communicated over the vehicle&#39;s data buses so as to be output via the vehicle&#39;s audio system or via the vehicle&#39;s built-in display. 
     System  100  may further include a data logger  106 , which may be included within central module  104  or may be provided separately and communicatively coupled to central module  104 . The data logger can include a storage device  107 , such as, for example, flash memory, a magnetic disc, an optical disc, or any other known non-volatile information storage medium that enables system  100  to function as described herein. Data logger  106  can store any or all data received by central module  104  as well as the results of any or all calculations performed by central module  104 . 
     System  100  can further include a communications port  108  communicatively coupled to central module  104 , for coupling system  100  to a computing device. Communications port  108  may be compliant with any known computing communications standard, for example USB, FireWire, Thunderbolt, and so forth, with wireless communication standards such as Bluetooth, IEEE 802.11, and so forth, or a proprietary wired or wireless communications hardware and protocols. When central module  104  is coupled to a computing device, any or all data received by central module  104  as well as the results of any or all calculations performed by central module  104  may be monitored in real-time via software provided on the computing device. Data stored by data logger  106  can also be accessed through software provided on the computing device, or may be downloaded onto the computing device, for example as a text file, a comma-separated value (.csv) file, or in a proprietary format. 
     System  100  may further include a display  110  communicatively coupled to central module  104 . Display  110  may be an LCD display, an OLED display, or any other display known in the art that enables system  100  to function as described herein. Display  110  may further be touch-sensitive. Physical controls may also be provided for controlling the functionality of system  100 . Any or all data received by central module  104  as well as the results of any or all calculations performed by central module  104  may be monitored in real-time via display  110 . Data stored by data logger  106  may be shown on display  110  as well. A user interface may be provided for display  110 , which may include diverse data display modes, user-configurable settings for system  100 , and any other features that may be contemplated or provided as desired. In an alternate embodiment, display  110  may be provided as a heads-up display that is projected onto the windshield of the vehicle such that it is visible to the driver. 
     Communicative coupling between central module  104  and the various components of system  100 , including sensor modules  102 , may be facilitated by a central wireless communications device  118  communicatively coupled to central module  104 . The central wireless communication device may utilize any known communications protocol, for example the IEEE 802.11 wireless communications protocol. The central wireless communication device may be adapted to communicatively couple to each sensor module  102  of the plurality of sensor modules that may be installed on the vehicle so as to receive data from the sensor modules. In some embodiments, communications with a computing device may be facilitated by central wireless communications device  118  in lieu of communications port  108 . 
     The above-described components of system  100  may be provided separately, or one or more of the components may be provided as a multi-component unit in a single enclosure. For example, in one embodiment, central module  104  may be placed in a location such as the vehicle&#39;s trunk or behind the dashboard, while data logger  106 , display  110 , and communications port  108  may be placed in a user-accessible location, for example attached to the dashboard or center console of the vehicle. Communications between the components may be wired or wireless, with each separately-provided component or multi-component unit including a wireless communication device communicatively coupled thereto. In another embodiment, central module  104 , data logger  106 , display  110  and communications port  108  may be provided as a single unit which may be placed in a user-accessible location. 
     Turning to  FIG. 1   c , each sensor module  102  may include a plurality of sensors  120 , a power source  124 , at least one wireless communications device  128 , and a microcontroller  122  communicatively and electrically coupled to sensors  120  and the at least one wireless communications device  128 . Sensor module  120  may further include an analog-to-digital signal converter  126 , which may include signal conditioners and amplifiers. At least one wireless communication device  128  included in sensor module  102  may be adapted to communicate with the central wireless communication device  118  of central module  104 . At least one wireless communication device  128  may further be adapted to communicate with the plurality of sensors  120  included in sensor module  102 . Power source  124 , wireless communications device  128 , and microcontroller  122  may be provided as a multi-component unit in a single enclosure, while sensors  120  may be disposed in certain locations on a rotating member of the vehicle, as described further below. 
     Sensors  120  may be strain gauges disposed on the surface of the rotating member of the vehicle. Additional sensors or gauges included in sensor module  102  may be, for example, pressure sensors, torque sensors, rotational velocity sensors, temperature sensors, or any other desired measuring devices. Sensors  120  can be communicatively coupled to microcontroller  122 . Communicative couplings between sensors  120  and microcontroller  122  may be wired, wireless or a combination thereof, depending on the sensor type. In the case of wired communicative couplings, power may also be provided to sensors  120  from power source  124  via the wire connection. In the case of wireless communicative couplings, sensors  120  may be based on surface acoustic wave (SAW) technology. In such a case, a wireless communication device  128  of sensor module  102  can emit signals at desired frequencies so as to excite the SAW-based sensors and can receive the resultant reply signals from the SAW-based sensors. 
     In one exemplary embodiment, signals received from sensors  120  by microcontroller  122  may be relayed as raw sensor data to central module  104  via a wireless communicative coupling between the central module and the sensor module  102 . The raw sensor data may then be processed by central processor  112 . In another exemplary embodiment, analog signals received from sensors  120  may first be processed by analog-to-digital signal converter  126  and then by microcontroller  122 , and the resultant data may be subsequently sent to central module  104  via the wireless communicative coupling between the modules. 
     Power source  124  may include a battery, for example a user-replaceable battery or a rechargeable battery. Power source  124  may further include a charging device, for example a kinetic charging device. As the sensor modules are provided as rotating members of the vehicle, the kinetic charging device can generate electric power from the rotation of the sensor module, for example by inductive coupling or by piezoelectric means, thereby charging the battery or powering the components of the sensor module. The kinetic charging device may have any desired arrangement, for example, a magnet and a coil both contained within the kinetic charging device, or a coil located within the charging device and a magnet located on a stationary member of the vehicle such that the coil passes proximate to the magnet during rotation of the rotating member of the vehicle. Power source  124  may further include shielding and noise cancellation devices so as to minimize electromagnetic interference between power source  124  and sensors  120 . 
     Turning to  FIGS. 2   a - 2   b , in one exemplary embodiment, the rotating member may be a torsion disc  200  adapted to be disposed between the axle  20  of a vehicle and the brake assembly  24  of the vehicle. 
     Torsion disc  200  can have a first face  202 , a second face  204 , an outer circumferential face  206  and an inner circumferential face  208 . First and second faces  202 ,  204  can be divided into a plurality of raised sectors  210 , projecting axially from face  202  or  204 , extending from the inner circumferential face  206  to outer circumferential face  208 , and separated by recessed sectors  212 . Raised sectors  210  can include radial edges  214  which can extend from the surfaces of raised sectors  210  to the surfaces of recessed sectors  212  and which can be substantially orthogonal thereto. Recessed sectors  212  can be sized equal to each other and can be sized greater than raised sectors  210 , which can likewise be sized equal to each other. The sectors can be disposed on faces  202 ,  204  such that the central radius of a raised sector  210  of first face  202  is aligned with the central radius of a recessed sector  212  of second face  204 , and vice versa. 
     Disposed substantially along the central radius of each raised sector  210  and projecting axially therefrom may be a stud  218  for coupling torsion disc  200  to an axle  20  of a vehicle as well as to a brake assembly  24  and a wheel  26  of the vehicle. Studs  218  of second face  204  may be inserted through corresponding receiving apertures  21  on a flange  22  of axle  20 , and axle coupling nuts  23  may be affixed thereto. Studs  218  of first face  202  can be inserted through corresponding receiving apertures  25  on brake assembly  24 , and through lug nut holes  27  of wheel  26 . Wheel coupling nuts  29 , for example lug nuts, may then be affixed to the studs, completing the assembly. In some embodiments, studs may also be attached to axle flange  22  or wheel  26  and protrude into the torsion disc  206 . 
     Such a configuration of torsion disc  200  facilitates the isolation of the load transfer plane between the mounting surfaces of first face  202  and second face  204  by separating the mounting surfaces into different planes. The separation of the mounting surfaces facilitates reducing or eliminating the preload forces between first face  202  and second face  204 , and reduces the likelihood of the transfer of shear forces between the studs mounted on first face  202  and the studs mounted on second face  204 . This can facilitate increased accuracy in the measurement of the strain forces by reducing or eliminating the unknown amount of load transfer that would exist in the event the mounting surfaces were not separated, wherein the preload force would be acting on the load transfer plane, resulting in load transfer via friction of the non-separated mounting surfaces. 
     Defined in the inner circumferential face  208  of torsion disc  200  may be a recess  216  that can be sized and configured to receive the components of the sensor module; however, recess  216  may be defined in any location on the torsion disc that does not detract from the functionality of system  100  as described herein. Such components may be power source  124 , microcontroller  122 , converter  126 , and wireless communication device  128 . Torsion disc  200  can further include balancing structures to offset the difference in weight and weight distribution resulting from recess  216  and the components therein. Such balancing structures may be a second recess disposed axially opposite recess  216  and including a counterweight substantially equal to the weight of the components in recess  216 , or any other known balancing structure that enables system  200  to function as described herein. 
     The plurality of sensors  120  may be disposed on first and second faces  202 ,  204  as well as outer circumferential face  206  of torsion disc  200 , or any other desired surface. The sensor modules may be placed at locations that experience greater deflection relative to the rest of torsion disc  200 , so as to increase the sensitivity of the strain measurements or any other measurements by the sensor module. Such locations may be determined for each torsion disc  200  prior to installation of the sensors. Exemplary locations may include, but are not limited to, on raised radial portions  210  proximate edge  214 , on recessed sectors  212  abutting edge  214 , on outer circumferential face  206 , and on the isolated torsional plane of torsion disc  200 . 
     The configuration of torsion disc  200  may be adapted for the bolt pattern of the particular vehicle on which system  100  is being installed. For example, in the illustrated embodiment of  FIGS. 2   a - 2   b , torsion disc  200  can be adapted for a five-lug bolt pattern, and can include five recessed sectors and five raised sectors on each of faces  210 ,  212 . Each recessed sector  212  can be a sector of approximately 40°, while each raised sector  210  can be a sector of approximately 32°. It should be appreciated that the number and angles of the raised and recessed sectors, as well as the positions of studs  218  along the central radii of the raised sectors can vary depending on the bolt pattern of the particular vehicle on which system  100  is being installed. Studs  218  may also be attached to the flange of axle  22  or to wheel  26  and protrude into torsion disc  200 . It should also be appreciated that any known coupling between torsion disc  200 , brake assembly  24  and wheel  26  may be contemplated and provided as desired. 
     Turning to  FIGS. 3   a - 3   c , in another exemplary embodiment, the rotating member may be a disc brake rotor  300  having a rotor portion  302  and a torsion disc  308 . Torsion disc  308  may be coupled to rotor portion  302  via any desired structure; for example, the torsion disc  308  may be provided as part of an inner flange  304 . 
     Rotor portion  302  may be any known disc brake rotor, may be made of any appropriate material, may be slotted, cross-drilled, ventilated, and may include any other desired features. Coupled substantially proximate the inner circumference of the rotor portion  302  can be inner flange  304 , which may have a substantially frusto-conical shape. Flange portion  304  can include an outer ring  306 , a torsion disc  308  concentric with and axially offset from outer ring  306 , and a bridging portion  310  connecting outer ring  306  to torsion disc  308 . 
     Torsion disc  308  can have a first face  312 , a second face  314 , an outer circumferential face  316  and an inner circumferential face  318 . First and second faces  312 ,  314  can be divided into a plurality of raised sectors  320 , projecting axially from face  312  or  314 , extending from the inner circumferential face  316  to outer circumferential face  318 , and separated by recessed sectors  322 . Raised sectors  320  can include radial edges  324  which can extend from the surfaces of raised sectors  320  to the surfaces of recessed sectors  322  and which can be substantially orthogonal thereto. Recessed sectors  322  can be sized equal to each other and can be sized greater than raised sectors  320 , which can likewise be sized equal to each other. The sectors can be disposed on faces  312 ,  314  such that the central radius of a raised sector  320  of first face  312  is aligned with the central radius of a recessed sector  322  of second face  314 , and vice versa. 
     Disposed substantially along the central radius of each raised sector  320  and projecting axially therefrom may be a stud  328  for coupling disc brake rotor  300  to an axle  30  of a vehicle and to a wheel  36  of the vehicle. Studs  318  of second face  314  may be inserted through corresponding receiving apertures  31  on a flange  32  of axle  30 , and axle coupling nuts  33  may be affixed thereto. Studs  328  of first face  312  can be inserted through lug nut holes  37  of wheel  36 . Wheel coupling nuts  38 , for example lug nuts, may then be affixed to the studs, completing the assembly. In some embodiments, studs may also be attached to axle flange  32  or wheel  36  and protrude into the torsion disc  308 . 
     Such a configuration of torsion disc  308  facilitates the isolation of the load transfer plane between the mounting surfaces of first face  312  and second face  314  by separating the mounting surfaces into different planes. The separation of the mounting surfaces facilitates reducing or eliminating the preload forces between first face  312  and second face  314 , and reduces the likelihood of the transfer of shear forces between the studs mounted on first face  312  and the studs mounted on second face  314 . This can facilitate increased accuracy in the measurement of the strain forces by reducing or eliminating the unknown amount of load transfer that would exist in the event the mounting surfaces were not separated, wherein the preload force would be acting on the load transfer plane, resulting in load transfer via friction of the non-separated mounting surfaces. 
     Defined in the inner circumferential face  316  of torsion disc  308  may be a recess  326  that can be sized and configured to receive the components of the sensor module; however, recess  326  may be defined in any location on the torsion disc that does not detract from the functionality of system  100  as described herein. Such components may be power source  124 , microcontroller  122 , converter  126 , and wireless communication device  128 . Torsion disc  308  can further include balancing structures to offset the difference in weight and weight distribution resulting from recess  326  and the components therein. Such balancing structures may be a second recess disposed axially opposite recess  326  and including a counterweight substantially equal to the weight of the components in recess  326 , or any other known balancing structure that enables system  100  to function as described herein. 
     The plurality of sensors  120  may be disposed on first and second faces  312 ,  314  as well as outer circumferential face  316  of torsion disc  308 . Sensors  120  may be placed at locations that experience greater deflection relative to the rest of torsion disc  308 , so as to increase the sensitivity of the strain measurements or any other measurements by the sensor module. Such locations may be determined for each torsion disc  308  prior to installation of the sensor. Exemplary locations may include, but are not limited to, on raised sectors  320  proximate edge  324 , on recessed sectors  322  abutting edge  324 , and on outer circumferential face  316  abutting connecting supports  330 , and on the isolated torsional plane of torsion disc  308 . 
     Torsion disc  308  may be coupled to rotor portion  302  via any desired structure. In one exemplary embodiment, the torsion disc may be coupled to the rotor portion as part of inner flange  304 , which can include an outer ring  306  and a bridging portion  310 . Outer ring  306  may be sized such that the inner circumference of outer ring  306  is substantially similar to the inner circumference of rotor portion  302 . Outer ring  306  can further be sized such that an overlap exists between outer ring  306  and rotor portion  302 , wherein the overlap is sufficient to securely couple flange portion  304  to rotor portion  302 . 
     Bridging portion  310  can connect torsion disc  308  to outer ring  306  and can have a substantially frusto-conical shape. Proximate outer ring  306 , bridging portion  310  can be substantially continuous, while proximate torsion disc  308 , bridging portion  310  can include a plurality of connecting supports  330  separated by gaps  332 . Each connecting support  330  can be disposed proximate a raised sector  320  of first face  312  such that the central radius of the raised sector and center line of the connecting support are substantially collinear. 
     The configuration of disc brake rotor  300  may be adapted for the bolt pattern of the particular vehicle on which system  100  is being installed. For example, in the illustrated embodiment of  FIGS. 3   a - 3   c , disc brake rotor  300  can be adapted for a five-lug bolt pattern, and can include five recessed sectors and five raised sectors on each of faces  312 ,  314  of torsion disc  308 . Each recessed sector  322  can be a sector of approximately 40°, while each raised sector  320  can be a sector of approximately 32°. It should be appreciated that the number and angles of the raised and recessed sectors, as well as the positions of studs  328  along the central radii of the raised sectors can vary depending on the bolt pattern of the particular vehicle on which system  100  is being installed. Studs  328  may also be attached to the flange of axle  32  or to wheel  36  and protrude into torsion disc  308 . It should also be appreciated that any known coupling between torsion disc  200 , brake assembly  24  and wheel  26  may be contemplated and provided as desired. 
     Turning to  FIGS. 4   a - 4   b , in another exemplary embodiment, the rotating member may be a wheel  400 . Wheel  400  may be made of any appropriate material, and may have any desired physical or ornamental configuration. Wheel  400  can include a rim  402  having an inner surface  404 , a disc  406  having an inner face  408 , spokes  410  or analogous structural members, and bores  412  for receiving lug nuts or bolts. Defined in a portion of disc  406  may be a recess  414  that can be sized and configured to receive the components of the sensor module. Such components may be power source  124 , microcontroller  122 , converter  126 , and wireless communication device  128 . In the illustrated embodiment, recess  414  may be defined substantially at the center of the inner face  408  of disc  406 . In other embodiments, recess  414  may be defined in a spoke  410  or analogous structural member of disc  406 , with balancing structures provided as necessary. In yet other embodiments, the components of sensor module  120  may be affixed to the inner surface  404  of rim  402 , with balancing structures provided as necessary. 
     The plurality of sensors  120  may be disposed on the inner face  408  of disc  406 . Sensors  120  may be placed at locations that experience greater deflection relative to the rest of disc  406 , so as to increase the sensitivity of the strain measurements or any other measurements by the sensor module. Such locations may be determined for each wheel  400  prior to installation of the sensor. Exemplary locations may include, but are not limited to, proximate the edges of spokes  410  or analogous structural members of disc  406 , and between bores  412 . In some embodiments, a torsion disc may be coupled to the inner surface  404  of rim  402 , and the sensors may be disposed on the isolated torsional plane of the torsion disc, substantially as described above. 
     Wheel  400  may be coupled to a vehicle using known coupling methods, for example by receiving studs  42  of a flange  41  of an axle  40  through bores  412 . Wheel coupling nuts  48 , for example lug nuts, may then be affixed to the studs, completing the assembly. The configuration of bores  412  of wheel  400  may be adapted for the bolt pattern of the particular vehicle on which system  100  is being installed. For example, in the illustrated embodiment of  FIGS. 4   a - 4   b , wheel  400  can be adapted for a five-lug bolt pattern; however, bores  412  may be disposed so as to be adapted for any known bolt pattern. Wheel  400  may further be adapted for vehicles having hub-centered wheel couplings. 
     Turning to  FIG. 5 , a process for real-time measurement of vehicle performance  500  may be disclosed. Subsequent to mounting a sensor module on the desired rotating member, the sensor module may be calibrated at step  502 . Calibration of the sensor module can include applying at least one torsional load having a known value to the rotating members, measuring the response of the sensor modules, and correlating the value of the torsional load to the sensor response so as to generate an empirical or analytical calibration curve. If desired, calibration of the sensor module can further include applying at least one additional force having a known magnitude and direction to the rotating members, measuring the response of the sensor modules, and correlating the magnitude and direction of the at least one directional force to the sensor response so as to generate at least one additional empirical or analytical calibration curve. Subsequent to calibration, the rotating members may be installed on the vehicle, and the calibration curve may be input into the central processor  112 . 
     In operation, when a load is applied to the rotating members on which sensor modules are mounted—for example due to acceleration or deceleration of the automobile, and/or due to lateral, vertical, forward, or rearward acting force—the sensors  120  that are strain gauges may be elastically deformed, thus allowing the strain on the strain gauges to be measured. Signals from sensors  120  may, at step  504  be communicated to microcontroller  122  of sensor module  120 , whereupon, at step  506 , the signals may be relayed as raw sensor data to central module  104 , or processed by analog-to-digital signal converter  126  and microcontroller  122  at step  506 , with the resultant data transmitted to central module  104  at step  508 . The measured strain values may further be conditioned using a temperature compensation circuit and filtering, wherein the temperature may be received from a sensor  120  that is a temperature sensor. 
     Data received by central module  104  may be processed by central processor  112 . The processing steps can include comparing the received data to the calibration curve input into processor  112 , thereby generating torque and directional force values. Engine RPM values may then be received by central processor  112  at step  510 , for example from a data bus of the vehicle, from a sensor that is a hall-effect sensor, or from any other device or method for determining engine revolution counts. At step  512 , horsepower values may be calculated according to the formula HP=(torque·RPM)/5252, or any alternative analysis method. The calculated values, along with any other data received from other sensors or from the vehicle&#39;s data bus can then be logged and stored by data logger  106  at step  514  and displayed on display  110  at step  516 . 
     Embodiments of system  100  can further include sensors to measure any existing Cartesian forces and moments on the rotating members on which the sensor modules are mounted. Sensors can therefore be included which can measure forces in the x, y and z planes, as well as moments in the x, y and z directions, or such measurements can be obtained from the vehicle&#39;s data bus, if available. These measurements can then be processed to generate data, including, but not limited to, data as to braking force, road-load power, traction-loss indication, vehicle weight, etc. Furthermore, the system can include sensors, adapters or capabilities for obtaining additional inputs, such as oxygen sensors, accelerometers, fuel consumption measurements, or any other desired characteristic. Such inputs can be used to determine, measure and report additional vehicle metrics such as fuel efficiency, stability, the effectiveness of the driver in controlling the vehicle, or any other desired metric. 
     Thus, the embodiments of system  100  described herein can provide the vehicle operator with real-time horsepower, torque, and other values during operation of the vehicle. Advantages of the embodiments of system  100  described herein can include, but are not limited to, measuring, displaying and logging power and torque output at the wheels of the vehicle, providing real-time data at any time while the vehicle is driven, and the ability to measure power, torque, and other performance variations stemming from vehicle modifications and driving conditions or techniques. Furthermore, as the sensor modules may be coupled to rotating members at each wheel of the vehicle, system  100  can gather separate data for each of the vehicle&#39;s wheels. 
     The foregoing description and accompanying figures illustrate the principles, preferred embodiments and modes of operation of the invention. However, the invention should not be construed as being limited to the particular embodiments discussed above. Additional variations of the embodiments discussed above will be appreciated by those skilled in the art. 
     Therefore, the above-described embodiments should be regarded as illustrative rather than restrictive. Accordingly, it should be appreciated that variations to those embodiments can be made by those skilled in the art without departing from the scope of the invention as defined by the following claims.