SE2250727A1

SE2250727A1 - Velocity measurement system

Info

Publication number: SE2250727A1
Application number: SE2250727A
Authority: SE
Inventors: Eivind Vikebö; Jimmy Engman; Ole Jonny Wärp
Original assignee: Ka Group Ag
Priority date: 2019-12-03
Filing date: 2019-12-03
Publication date: 2022-06-16
Also published as: DE112019007930T5; WO2021111170A1; CN114787635A

Abstract

Systems and methods for determining a speed of a vehicle. The vehicle includes a sensor ring coupled to and rotatable with a propulsion component of the vehicle, and includes a rotation sensor proximate the sensor ring. The rotation sensor generates a first and second signal each corresponding to a rotation of the sensor ring caused by a rotation of the propulsion component. At least one of the first signal or the second signal includes distortion. A processor is configured to construct a third signal from the first signal, divide the third signal by the second signal to produce a fourth signal, and determine a velocity of the vehicle based on the fourth signal.

Description

VELOCITY MEASUREMENT SYSTEM BACKGROUND[0001] Drivers rely on a vehicle”s speed gauge to ensure compliance with driving laws andavoid dangerous maneuvers, and several vehicle control functions rely on vehicle velocity as aninput parameter. Vehicles should thus be configured to detennine and report vehicle velocity rapidly and With a high degree of precision.

SUMMARY 2. 2. 2. id="p-2" id="p-2"

[0002] In one example, a method for measuring a velocity of a vehicle including a sensorring coupled to and rotatable With a propulsion component of the vehicle and a rotation sensorproximate the sensor ring that generates signals corresponding to a rotation of the sensor ringincludes generating, by the rotation sensor, a first signal and a second signal. Each of the first andsecond signals corresponds to a rotation of the sensor ring caused by a rotation of the propulsioncomponent. At least one of the first signal or the second signal includes distortion. The methodfurther includes constructing a third signal from the first signal, generating a fourth signal byperformance of a division operation using the third signal and the second signal, and determininga speed and/or moving direction of the vehicle based on the fourth signal. 3. 3. 3. id="p-3" id="p-3"

[0003] In a further example, a velocity measurement system for a vehicle includes a sensorring coupled to and rotatable With a propulsion component of the vehicle. The system also includesa rotation sensor proximate the sensor ring that, responsive to a rotation of the sensor ring,generates a first signal and a second signal each corresponding to the rotation of the sensor ring.At least one of the first signal or the second signal includes distortion. The system further includesa controller operatively coupled to the rotation sensor. The controller is configured to construct athird signal from the first signal, generate a fourth signal by performance of a division operationusing the third signal and the second signal, and determine a speed and/or moving direction of the vehicle based on the fourth signal.

BRIEF DESCRIPTION OF THE DRAWINGS[0004] FIG. l is a schematic diagram illustrating a velocity measurement system of a vehicle. . . . id="p-5" id="p-5"

[0005] FIG. 2 is a flowchart illustrating a method for deterrnining vehicle Velocity. 6. 6. 6. id="p-6" id="p-6"

[0006] FIG. 3 is a graph illustrating signals that may be generated by a rotation sensor inthe system of FIG. 1. 7. 7. 7. id="p-7" id="p-7"

[0007] FIG. 4 is a graph illustrating phase angles corresponding to the signals of FIGS. 3.[0008] FIG. 5 is a graph illustrating a signal that may be generated from the signals of FIG. 3 to determine vehicle Velocity.

DETAILED DESCRIPTION 9. 9. 9. id="p-9" id="p-9"

[0009] Electromagnetic sensors for measuring vehicle velocity are susceptible to noise,which may linearly increase as a function of increasing velocity. For example, vehicle componentsproximate to such a sensor may interfere with magnetic fields measured by the sensor, and maythereby introduce distortion in the sensor”s output. To compensate for this distortion anddetermine vehicle velocity, a vehicle may be configured to apply relatively complex frequencyfilters and counters to the sensor”s output. These processes increase the time needed to detenninevehicle velocity, which may have changed by the time the determined velocity is reported to thedriver or to other functions of the vehicle dependent on vehicle velocity (e.g., control anddiagnostic functions). . . . id="p-10" id="p-10"

[0010] FIG. 1 illustrates a system 100 of a vehicle 102 that may determine a velocity ofthe vehicle 102 without using the relatively complex frequency filters and counters describedabove. As a result, the system 100 may determine and report the vehicle”s 102 velocity in lesstime. The time between the vehicle 102 traveling at a given velocity and the driver and othervehicle functions becoming aware of this velocity may thus be reduced, thereby improving driverawareness and the performance of velocity-dependent vehicle functions. 11. 11. 11. id="p-11" id="p-11"

[0011] The system 100 may include a sensor ring 104, a rotation sensor 106, and acontroller 108. The sensor ring 104 may be coupled to a propulsion component of the vehicle 102.The propulsion component may rotate with movement of the vehicle 102 in the forward or reversedirection. For instance, the propulsion component may rotate, such as under the power of anengine of the vehicle 102, to propel the vehicle 102 in the forward or reverse direction. As anexample, the propulsion component may be a part of the drivetrain of the vehicle 102. Thedirection and rate of rotation of the propulsion component may correspond to the velocity of the vehicle 102. The sensor ring 104 may form a concentric relationship with the propulsion component, and may rotate With the propulsion component. The direction and rate of rotation ofthe sensor ring 104 may thus also correspond to the Velocity of the vehicle 102. 12. 12. 12. id="p-12" id="p-12"

[0012] As shown in the illustrated example, the propulsion component may be a rod 110,such as a drive shaft or axle shaft of the vehicle 102. In this case, the sensor ring 104 may becoupled to the propulsion component by being Wrapped around the rod 110. As another example,the propulsion component may be a wheel of the vehicle 102. In this case, the sensor ring 104may be coupled to the propulsion component by being mounted to an inside surface of the wheel.The sensor ring 104 may also be coupled to and rotatable with multiple propulsion components ofthe vehicle 102 at the same time, such as both a rod 110 of the vehicle 102 and a wheel of thevehicle 102 attached to the rod 110. 13. 13. 13. id="p-13" id="p-13"

[0013] The sensor ring 104 may include a plurality features 112 distributed along andforming a curved outer surface of the sensor ring 104. The features 112 may encircle the rotationalaxis of the sensor ring 104, and may face radially outward from the rotational axis of the sensorring 104. The features 112 may be evenly distributed along the outer surface of the sensor ring104 such that the size of each feature 112 along the outer surface is substantially equal. Thefeatures 112 may rotate with the sensor ring 104. Correspondingly, the direction and rate ofrotation of the features 112 may also correspond to the Velocity of the vehicle 102. 14. 14. 14. id="p-14" id="p-14"

[0014] Responsive to rotation of the sensor ring 104, the rotation sensor 106 may generatesignals corresponding to the rotation of the sensor ring 104 and indicating the Velocity of thevehicle 102. In particular, the rotation sensor 106 may include a plurality of sub-sensors 116, suchas a sub-sensor 116A and a sub-sensor 116B. Each sub-sensor 116 may be configured to detectwhen a feature 112 of the sensor ring 104 rotates past the rotation sensor 106, and to generate asignal indicative of feature 112 passage over time. The frequency of the signals generated by thesub-sensors 116 may reﬂect the rotation rate of the sensor ring 104, and may thus correspond tothe speed of the Vehicle 102. As explained in more detail below, the timing of the generated signalsmay reﬂect the direction of rotation of the sensor ring 104. . . . id="p-15" id="p-15"

[0015] The sub-sensors 116 may be hall-effect sensors configured to detect magnetic fieldsformed between the features 112. In particular, the features 112 may include one or more northpole features 112A and one or more south pole features 112B. The one or more north pole features112A may be interspaced with the one or more south pole features 112B along the outer surface of the sensor ring 104. Under this arrangement, each pair of adjacent features 112 may form a magnetic field. As the sensor ring 104 rotates With movement of the vehicle 102, the magnitudeand direction of the magnetic field applied to the rotation sensor 106 may regularly ﬂuctuate Withthe changing angular positions of the features 112 relative to the rotation sensor 106. Each sub-sensor 116 may thus be configured to output a periodic signal indicating these ﬂuctuations overtime, the frequency of Which may correspond to the rotation rate of the sensor ring 104. 16. 16. 16. id="p-16" id="p-16"

[0016] Each sub-sensor 116 may be configured to measure a different axial component117 of the magnetic field applied to the rotation sensor 106. For instance, the sub-sensor 116Amay be configured to measure the magnetic field along an axis 117A tangential to the rotationalmovement of the sensor ring 104, and the sub-sensor 116B may be configured to measure themagnetic field along an axis 117B that is normal to the rotational movement of the sensor ring104. Under this arrangement, rotation of the sensor ring 104 may cause the sub-sensors 116 togenerate sinusoidal signals phase shifted by ninety degrees. The rotation direction of the sensorring 104, and correspondingly the movement direction of the vehicle 102, may be indicated basedon Whether the signal generated by the sub-sensor 116A leads the signal generated by the sub-sensor 116B, or vice versa. 17. 17. 17. id="p-17" id="p-17"

[0017] Specifically, as rotation of the sensor ring 104 causes a feature 112A to be centeredon the rotation sensor 106, the sub-sensor 116A may output a signal level indicative of a minimummagnetic field magnitude (e. g. , zero), and the sub-sensor 116B may output a signal level indicativeof a maximum magnetic field magnitude in a given direction (e. g., one). Further rotation of thesensor ring 104 may then cause the feature 112A and an adjacent feature 112B be equidistant fromthe rotation sensor 106. In this position, depending on the rotation direction of the sensor ring 104,the sub-sensor 116A may output a signal level indicative of a maximum magnetic field magnitudein the given direction (e. g., one), or may output a signal level indicative of a maximum magneticfield in a direction opposite the given direction (e.g., negative one). The sub-sensor 116B mayoutput a signal level indicative of a minimum magnetic field magnitude (e. g. , zero). As continuedrotation then causes the feature 112B to be centered on the rotation sensor 106, the sub-sensor116A may again output a signal level indicative of a minimum magnetic field magnitude (e.g.,zero), the sub-sensor 116B may output a signal level indicative of a maximum magnetic fieldmagnitude in the direction opposite the given direction (e.g., negative one). Additional rotationmay thereafter cause the feature 112B and another feature 112A to be equidistant from the rotation sensor 106. ln this position, the sub-sensor 116A may output a signal level opposite the signal level previously output by the sub-sensor 116A to indicate a maximum magnetic field magnitude(e.g., negative one if previously one, or one if previously negative one), and the sub-sensor 116Bmay again output a signal level indicative of a minimum magnetic field magnitude (e.g., zero).[0018] Thus, continuous rotation of the sensor ring 104 may cause the sub-sensors 116 togenerate sinusoidal signals phase shifted by ninety degrees. The output for one of the sub-sensors116, such as the sub-sensor 116A, may be labeled as a cosine signal output, and the output for theother sub-sensor 116, such as the sub-sensor 116B, may be labeled as a sine signal output. Rotationof the sensor ring 104 in a given direction may cause the sine signal from the sine signal output tolead the cosine signal from the cosine signal output by ninety degrees, and rotation of the sensorring 104 in a direction opposite the given direction may cause the cosine signal from the cosinesignal output to lead the sine signal from the sine signal output by ninety degrees. 19. 19. 19. id="p-19" id="p-19"

[0019] The rotation sensor 106 may be configured to communicate the signals generatedby the sub-sensors 116 to the controller 108 for processing. Ideally, the signals generated by thesub-sensors 116 Would be clean phase-shifted periodic signals of a substantially same frequencyand amplitude. As described above, however, at least one these signals may be distorted by othercomponents proximate the rotation sensor 106. For instance, the illustrated example shows amagnetic component 118 proximate the sensor ring 104. The magnetic component 118 mayinterfere With the magnetic field measured by one of the sub-sensors 116, such as the sub-sensor116B. The amount of distortion caused by the interference may be proportional to the velocity ofthe vehicle 102. As some non-limiting examples, the magnetic component 118 may be a surfaceof a Wheel, differential, joint, transmission, engine, or clutch of the vehicle 102. . . . id="p-20" id="p-20"

[0020] Specifically, as the sensor ring 104 rotates With movement of the vehicle 102, themagnetic component 118 may interfere With the magnetic field component generated by thefeatures 112 and measured by the sub-sensor 116B, such as by reducing the magnitude of themeasured magnetic field component. Accordingly, the amplitude of the sine signal generated bythe sub-sensor 116B may be reduced. The amount of distortion of the sine signal may linearlyincrease as the velocity of the vehicle 102 increases. Notwithstanding such distortion, the system100, or more particularly the controller 108, may be configured to determine the velocity of thevehicle 102 from the sine signal Without applying complex frequency filters and counters. 21. 21. 21. id="p-21" id="p-21"

[0021] The controller 108 may include a processor 120, memory 122, mass storage 124, and an input/output (I/O) interface 126. The controller 108 may be operatively coupled to an in communication With one or more external resources via the I/O interface 126. The externalresources may include, Without limitation, electronic control units (ECUs) 128, a display 130, andthe rotation sensor 106. 22. 22. 22. id="p-22" id="p-22"

[0022] The processor 120 may include one or more devices selected from microprocessors,micro-controllers, digital signal processors, microcomputers, central processing units, fieldprogrammable gate arrays, programmable logic devices, state machines, logic circuits, analogcircuits, digital circuits, or any other devices that manipulate signals (analog or digital) based onoperational instructions stored in the memory 122. The memory 122 may include a single memorydevice or a plurality of memory devices including, but not lirnited, to read-only memory (ROM),random access memory (RAM), volatile memory, non-volatile memory, static random accessmemory (SRAM), dynamic random access memory (DRAM), ﬂash memory, cache memory, orany other device capable of storing information. The mass storage 124 may include one or morepersistent data storage devices such as a hard drive, optical drive, tape drive, non-volatile solid-state device, or any other device capable of persistently storing information. 23. 23. 23. id="p-23" id="p-23"

[0023] The processor 120 may operate under the control of an operating system (O/S) 132and one or more computer software applications, such as a velocity application 134, residing inmemory 122. The O/S 132 may be configured to manage controller resources so the velocityapplication 134 may be executed by the processor 120. Altematively, the processor 120 mayexecute the velocity application 134 directly, in Which case the O/S 132 may be omitted. The O/S132 and velocity application 134 may each be configured, upon execution by the processor 120,to implement the functions, features, and processes of the controller 108 described herein.Specifically, the O/S 132 and velocity application 134 may each be embodied by a set of computer-executable instructions residing in memory 122 and compiled or interpreted from a variety ofprogramming languages and/or technologies, including, Without limitation, and either alone or incombination, Java, C, C++, C#, Objective C, Fortran, Pascal, Java Script, Python, Perl, andPL/SQL. Each set of computer-executable instructions may be configured, upon execution by theprocessor 120, to cause the processor 120 to implement the functions, features, and processes ofthe program embodied by the instruction set. The memory 122 may also include one or more datastructures used by the processor 120, O/S 132, and/or velocity application 134 to store and manipulate data. 24. 24. 24. id="p-24" id="p-24"

[0024] As an example, the velocity application 134 may be configured, upon execution bythe processor 120, to receive signals from the rotation sensor 106 corresponding to a movement ofthe vehicle 102. At least one of the signals may include distortion induced by other componentsof the vehicle 102. The velocity application 134 may be configured to generate a division signalfrom the received signals that ratiometrically indicates the velocity of the vehicle 102. The velocityapplication 134 may be configured to then determine the velocity of the vehicle 102 based on thedivision signal. Additional details of this process are described in more detail below. . . . id="p-25" id="p-25"

[0025] A database, such as a velocity table 136, may reside on the mass storage 124, andmay be used to collect and organize data used by the velocity application 134. The database mayinclude data and supporting data structures that store and organize the data. The database may bearranged with any database organization or structure including, but not limited to, a relationaldatabase, a hierarchical database, a network database, or combinations thereof. A databasemanagement system in the form of a computer software application executing as instructions onthe processor 120 may be used to access the information or data stored in records of the databasein response to a query, where a query may be dynamically determined and executed by the O/S132 or velocity application 134. 26. 26. 26. id="p-26" id="p-26"

[0026] The velocity table 136 may be a stored lookup table including data associating aplurality of signal characteristics with different vehicle speeds. Specifically, the velocity table 136may be generated by propelling the vehicle 102 at various speeds as indicated by an external speedsensor, identifying a characteristic from the signals generated by the rotation sensor 106 for eachspeed, and associating the signal characteristic with the speed for which the signal characteristicwas identified in the velocity table 136. Upon later execution by the processor 120, the velocityapplication 134 may be configured to query the velocity table 136 based on the signals receivedfrom the rotation sensor 106 to determine the speed of the vehicle 102. 27. 27. 27. id="p-27" id="p-27"

[0027] The I/O interface 126 of the controller 108 may provide one or more machineinterfaces that operatively couple the processor 120 to other devices and systems, such as the ECUs128, display 130, and rotation sensor 106. The velocity application 134 may thereby workcooperatively with extemal resources by communicating via the I/O interface 126 to provide thevarious features, functions, applications, processes, and modules of the controller 108 described herein. 28. 28. 28. id="p-28" id="p-28"

[0028] For instance, responsive to deterrnining a speed of the vehicle 102, the velocityapplication 134 may be configured to communicate the speed of the vehicle 102 to the display 130.The display 130 may be a speed gauge in view of the driver of the vehicle 102. The velocityapplication 134 may also be configured to communicate a determined vehicle velocity to the ECUs128. Similar to the controller 108, each ECU 128 may include a processor, mass storage, andmemory storing computer-executable instructions that, upon execution by the processor, cause theprocessor to implement functions, features, and processes of the ECU 128. The ECUs 128 mayeach be configured to implement one or more vehicle functions that depend on vehicle speedand/or direction. For example, one of the ECUs 128 may be configured to implement cruisecontrol functionality by comparing a current vehicle speed received from the controller 108 to aset vehicle speed. Another ECU 128 may be configured to implement anti-lock braking bymonitoring for rapid decelerations based on vehicle speeds received from the controller 108. Bydeterrnining vehicle velocity Without performing relatively complex frequency filtering andcounting, the controller 108 may reduce the time in Which the ECUs 128 become aware of thevehicle°s speed and/or direction, thus improving reactivity of the vehicle functions implementedby the ECUs 128. 29. 29. 29. id="p-29" id="p-29"

[0029] FIG. 2 illustrates a method 200 for determining a velocity of the vehicle 102. Thecontroller 108 may be configured, such as upon execution of the velocity application 134, toperform the method 200. . . . id="p-30" id="p-30"

[0030] In block 202, the controller 108 may receive signals from the rotation sensor 106.The received signals may correspond to a rotation of the sensor ring 104 caused by movement ofthe vehicle 102, as discussed above. Each received signal may be generated by a different sub-sensor 116 of the rotation sensor 106, and may reﬂect a rotation rate of the features 112 past therotation sensor 106. At least one of the received signals may be distorted by interference. If bothsignals are distorted, the level of distortion of one signal may differ from that of the other signal.The distortion may be proportional to the speed of the vehicle 102. 31. 31. 31. id="p-31" id="p-31"

[0031] As discussed above, the sub-sensors 116 may be configured to generate sinusoidalsignals phase shifted by ninety degrees. The output from one of the sub-sensors 116, such as thesub-sensor 116A, may be labeled as the cosine signal output, and the output of the other sub-sensor116, such as the sub-sensor 116B, may be labeled as a sine signal output. Thus, the signal output from the sub-sensor 116A may be considered as a cosine signal, and the signal output from the sub-sensor 116B may be considered as a sine signal. FIG. 3 illustrates a cosine signal 302 thatmay be generated by the sub-sensor 116A, and a sine signal 304 that may be generated by the sub-sensors 116B, during a movement of the vehicle 102 in which velocity is increased. As the Velocityof the vehicle 102 increases, which is reﬂected in the cosine signal 302 and sine signal 304 by anincreasing frequency, the amplitude of the sine signal 304 may become increasingly distorted. Inthe illustrated example, the cosine signal 302 is relatively undistorted. 32. 32. 32. id="p-32" id="p-32"

[0032] Referring again to FIG. 2, in block 204, the controller 108 may generate areconstructed signal from one of the signals received from the rotation sensor 106. Specifically,the controller 108 may construct a new signal from one of the signals received from the rotationsensor 106, such as the relatively undistorted signal, that matches the phase of the other signalreceived from the rotation sensor 106, such as the relatively distorted signal. The new signalconstructed from one of the signals received from the rotation sensor 106 may be referred to as areconstructed version of the other signal received from the rotation sensor 106 (e.g., areconstructed sine signal generated from the cosine signal 302, a reconstructed cosine signalgenerated from the sine signal 304). 33. 33. 33. id="p-33" id="p-33"

[0033] The controller 108 may be configured to generate the reconstructed signal byrectifying and applying a phase shift to one of the signals received from the rotation sensor 106that aligns the signal with the other signal received from the rotation sensor 106. Specifically,assuming the rotation sensor 106 is configured to generate sinusoidal signals phase shifted byninety degrees (e. g., the cosine signal 302 and sine signal 304), the controller 108 may calculatethe angles of one of the signals received from the rotation sensor 106 over time. To this end, thecontroller 108 may apply an inverse trigonometric function (e. g. , inverse sine or inverse cosine) to one of the signals under certain quadrant assumptions. If applying the inverse sine function, the controller 108 may be configured to assume the result is within quadrants I and IV (i. e. , from å to - å, inclusive). If applying the inverse cosine function, the controller 108 may be configured to assume that the result is within quadrants I and II (i.e., from 0 to n, inclusive). FIG. 4 illustratesa cosine angle waveform 306 showing the angles generated from the cosine signal 302 using theinverse cosine function, and a sine angle Waveform 308 showing angles generated from the sinesignal 304 using the inverse sine function. 34. 34. 34. id="p-34" id="p-34"

[0034] The controller 108 may be configured to generate the reconstructed signal from the deterrnined angles by biasing the angles by an amount equal to the configured phase shift, and applying the trigonometric function of which the inverse Was used to calculate the angles to thebiased angles. Specifically, assuming the signals received from the rotation sensor 106 are sinusoidal signals phase shifted by ninety degrees, the controller 108 may be configured to add or subtract g to or from the angles. For instance, if the angles are generated using the inverse sine function, then the controller 108 may be configured to add g to the angles and then apply the sine function to the biased angles to generate the reconstructed signal. Equivalently, the controller 108 may be configured to generate the reconstructed function by applying the cosine function to the angles calculated using the inverse sine function, Without explicitly adding å to the angles. If the angles are generated using the inverse cosine function, then the controller 108 may be configured to subtract å from the angles and then apply the cosine function to the biased angles to generate the reconstructed signal. Equivalently, the controller 108 may be configured to generate the reconstructed function by applying the sine function to the angles calculated using the inverse cosine function, Without explicitly subtracting g from the angles. . . . id="p-35" id="p-35"

[0035] FIG. 3 illustrates a reconstructed signal 310 generated from the cosine signal 302by applying the inverse cosine function to the cosine signal 302 to generate the cosine angleWaveforrn 306, and then applying the sine function to the cosine angle Waveforrn 306. As shownin the illustrated example, the reconstructed signal 310 may be a rectified signal in phase With theother signal (e.g., sine signal 304) received from the rotation sensor 106. 36. 36. 36. id="p-36" id="p-36"

[0036] Referring again to FIG. 2, responsive to generating the reconstructed signal 310,the controller 108 may be configured to generate a ratio signal by performance of a divisionoperation using the reconstructed signal and the other signal received from the rotation sensor 106.Specifically, in block 206, the controller 108 may bias the reconstructed signal and the other signalreceived from the rotation sensor 106 to tune random noise towards the sensitivity of the velocitydependency. Prior to biasíng these signals, one or both of the signals may cross zero. To avoidan undefined result in the division operation, the controller 108 may be configured to bias thereconstructed signal and the other signal so that neither of these signals crosses zero. Thecontroller 108 may be configured to bias the reconstructed signal and the other signal by adding apredefined value to both signals that causes each signal to be positive. As an example, referringto the sine signal 304 and the reconstructed signal 310 illustrated in FIG. 3, the controller 108 may be configured to add a value of three to each signal. 37. 37. 37. id="p-37" id="p-37"

[0037] In block 208, the controller 108 may generate the ratio signal (also referred to hereinas “division signal”) by performing a division operation using the biased reconstructed signal andthe biased other signal received from the rotation sensor 106. For instance, the controller 108 maybe configured to generate the division signal by dividing the biased reconstructed signal by thebiased other signal. Notwithstanding the presence of distortion in the signals received from therotation sensor 106, as the speed of the vehicle 102 ﬂuctuates, the division signal may ﬂuctuate inproportion to the change in speed. The division signal may thus ratiometrically indicate the speedof the vehicle 102. 38. 38. 38. id="p-38" id="p-38"

[0038] FIG. 5 illustrates a division signal 312 that may be generated by dividing the biasedreconstructed signal 310 by the biased sine signal 304, Where each of the reconstructed signal 310and sine signal 304 have been biased by adding a predefined value of three to each signal. Asshown in the illustrated example, the division signal 312 may include several peaks 314 extendingfrom reference portions 316 of the division signal 312. The peak 314 values decrease as thevelocity of the vehicle 102 increases. Each peak 314 of the division signal 312 may thuscorrespond to a speed of the vehicle 102 at the time instance When the peak 314 occurs. Asexplained in more detail below, the timing of the peaks 314 relative to the signal from Which thereconstructed signal Was generated (e. g. , relative to the cosine signal 302) may indicate the movingdirection of the vehicle 102. 39. 39. 39. id="p-39" id="p-39"

[0039] In the example illustrated in FIG. 5, the peaks 314 of the division signal 312 extendupWards from the reference portions 316 of the division signal 312. In alternative examples, thecontroller 108 may be configured to generate division signals such that the peaks 314 extenddoWnWards from the reference portions 316. For instance, rather than divide the reconstructedsignal 310 by the sine signal 304 to generate the division signal 312, the controller 108 may beconfigured to divide the sine signal 304 by the reconstructed signal 310, Which may result in thepeaks 314 of the division signal 312 extending doWnWards from the reference portions 316. As afurther example, rather than generating a positive reconstructed signal 310, the controller 108 maybe configured to generate a negative reconstructed signal by applying a phase shift opposite thosedescribed above, Which may result in the peaks 314 of the division signal 312 extendingdoWnWards from the reference portions 316. 40. 40. 40. id="p-40" id="p-40"

[0040] In block 210, the controller 108 may determine values of the division signal at a predefined angle, Which may correspond to the peaks 314 of the division signal. In particular, the 11 controller 108 may be configured to determine each time instance When the signal from Which thereconstructed signal is generated is at a predefined angle, such as based on a cosine or sine angleWaveform generated from the signal. For instance, assuming the rotation sensor 106 is configuredto generate sínusoídal signals With a ninety degree phase shift, the controller 108 may be configured to determine each time instance the inverse cosine of the signal from Which the reconstructed signal is generated is or equivalently each time instance the inverse sine of the signal from Which the reconstructed signal is generated is zero, taking into consideration thequadrant assumptions described above. Every other one of these time instances may correspondto a peak 314 in the division signal. For instance, the division signal 312 illustrated in FIG 5 includes a peak 314 every other time instance that the cosine angle Waveform 306 illustrated in FIG. 4 generated from the cosine signal 302 signal illustrated in FIG. 3 is g (and equivalently every other time instance that the inverse sine of the cosine signal 302 is zero). The time instancesbetween the time instances corresponding to the peaks 314 may correspond to reference portions316 in the division signal. 41. 41. 41. id="p-41" id="p-41"

[0041] The controller 108 may thus be configured to identify the peak 314 values of thedivision signal by evaluating the division signal at each time instance the signal from Which thereconstructed signal is generated corresponds to the predefined angle. For instance, at each suchtime instance, the controller 108 may be configured to determine Whether the value of the divisionsignal is greater than a threshold value (e.g., 1.2) (or less than a threshold value if the controller108 is configured to generate division signals such that the peaks 314 extend doWnWards from thereference portions 316). If so, then the controller 108 may be configured to identify the value asa peak 314 value of the division signal. As a further example, for each pair of adjacent timeinstances in Which the signal from Which the reconstructed signal is generated corresponds to thepredefined angle, the controller 108 may be configured to determine a value of the division signalat each time instance of the pair. The controller 108 may then be configured to determine that thegreater of the division signal values determined for the time instance pair (or the lesser of if thecontroller 108 is configured to generate division signals such that the peaks 314 eXtend doWnWardsfrom the reference portions 316) is a peak 314 value of the division signal. 42. 42. 42. id="p-42" id="p-42"

[0042] In block 212, the controller 108 may determine a velocity of the vehicle 102 basedon the peak 314 values of the division signal and the velocity table 136. In particular, to build the velocity table 136, the vehicle 102 may be driven at various speeds as measured by an external 12 sensor. For each speed, a division signal may be generated from the signals generated by therotation sensor 106 while the vehicle 102 travels at that speed, as described above. The divisionsignal may similarly include a plurality of peaks, each occurring at a time instance when the signalfrom which the reconstructed was generated corresponds to the predefined angle. A value basedon the peaks of the division signal may be determined and associated with the speed in the velocitytable 136. The determined value may equal the greatest (or lowest) peak value or an average ofthe peak values. During later operation of the vehicle 102, the controller 108 may determine aspeed of the vehicle 102 by querying the velocity table 136 based on one or more peak 314 valuesof a division signal determined using a predefined angle as described above, and responsivelyreceiving one or more speeds corresponding to the one or more peak 314 values from the velocitytable 136. In one example, the controller 108 may be configured to average the received speedsto determine a speed of the vehicle 102. 43. 43. 43. id="p-43" id="p-43"

[0043] If the velocity table 136 does not include a speed entry for a determined divisionsignal peak 314 value, the controller 108 may be configured to interpolate a speed correspondingto the peak value from the entries in the velocity table 136 surrounding the peak value. Forinstance, the controller 108 may be configured to identify the highest division signal peak valueless than the determined division signal peak 314 value and the lowest division signal peak valuegreater than the deterrnined division signal peak 314 value in the velocity table 136. Each of thehighest division signal peak value and the lowest division signal peak value may be associatedwith a different speed in the velocity table 136. The controller 108 may be configured to determinethat the determined division signal peak 314 value corresponds to a given speed in which a ratioof the difference between the given speed and the speed associated with the lowest division signalpeak value to the difference between the speed associated with the highest divisional signal peakvalue and the given speed is substantially equal to a ratio of the difference between the lowestdivision signal peak value and the determined division signal peak 314 value to the differencebetween the determined division signal peak 314 value and the highest division signal peak value.[0044] The controller 108 may be configured to determine the moving direction of thevehicle 102 based on a characteristic of the signal from which the reconstructed signal is generatedwhen the peaks 314 occur in the division signal. As described above, rotation of the sensor ring104 in one direction may cause the signal generated by the sub-sensor 116A to lead the signal generated by the sub-sensor 116B, and rotation of the sensor ring 104 in the other direction may 13 cause the signal generated by the sub-sensor 116A to lag the signal generated by the sub-sensor116B. Assuming the rotation sensor 106 is configured to generate sinusoidal signals phase shiftedby ninety degrees, depending on Whether the signal used to generate the reconstruction signal isthe leading signal or lagging signal, the peaks 314 of the division signal may occur When the signalfrom Which the reconstruction signal is generated exhibits a different characteristic. The controller108 may thus be configured to determine the movement direction of the vehicle 102 based on acharacteristic of the signal from Which the reconstructed signal is generated When the peaks 314occur in the division signal. 45. 45. 45. id="p-45" id="p-45"

[0045] Specifically, if the signal from Which the reconstructed signal is generated is theleading signal, then the peaks 314 of the division signal may occur during transitions of the signalfrom Which the reconstructed signal is generated from a minimum value to a maximum value (i.e. ,during a positive slope). Altematively, if the signal from Which the reconstructed signal isgenerated is the lagging signal, the peaks 314 of the division signal may occur during transitionsof the signal from Which the reconstructed signal is generated from a maximum value to aminimum value (i.e., during a negative slope). For instance, referring to FIGS. 3-5, because thecosine signal 302 is leading the sine signal 304, the peaks 314 of the division signal 312 may occurWhen the cosine signal 302 has a positive slope. If the cosine signal 302 Were lagging the sinesignal 304, then the peaks 314 of the division signal 312 may occur When the cosine signal 302has a negative slope. 46. 46. 46. id="p-46" id="p-46"

[0046] The controller 108 may thus be configured to determine a movement direction ofthe vehicle 102 by determining Whether the peaks 314 of the division signal occur When the signalfrom Which the reconstructed signal is generated has a positive slope or a negative slope.Responsive to the peaks 314 occurring When the signal from Which the reconstructed signal isgenerating has a positive slope, the controller 108 may be configured to determine that the vehicle102 is moving in a given direction (e.g., forward), and responsive to the peaks 314 occurring Whenthe signal from the reconstructed signal is generated has a negative slope, the controller 108 maybe configured to determine that the vehicle 102 is moving in an opposite direction (e. g., reverse).Which of the positive slope and negative slope corresponds to Which moving direction may bedeterrnined empirically and preprogrammed into the controller 108, such as part of the velocity application 134. 14 47. 47. 47. id="p-47" id="p-47"

[0047] Referring again to FIG. 2, in block 214, the controller 108 may communicate thedeterrnined speed and/or direction to the display 130 for illustration to the driver and/or to the oneor more ECUs 128 dependent on such items, as discussed above. 48. 48. 48. id="p-48" id="p-48"

[0048] The examples described herein may enable detennining vehicle velocity fromdistorted signals without using complex frequency filtering and counting. As a result, the timebetween the vehicle traveling at a given velocity and the driver and other vehicle functionsbecoming aware of this velocity may be reduced. Such faster reporting may improve driverawareness and the performance of velocity-dependent vehicle functions by enabling fasterreactions to change in vehicle velocity. 49. 49. 49. id="p-49" id="p-49"

[0049] In general, the routines executed to implement the embodiments of the invention,whether implemented as part of an operating system or a specific application, component,program, object, module or sequence of instructions, or even a subset thereof, may be referred toherein as "computer program code," or simply "program code. " Program code typically comprisescomputer readable instructions that are resident at various times in various memory and storagedevices in a computer and that, when read and executed by one or more processors in a computer,cause that computer to perform the operations necessary to execute operations and/or elementsembodying the various aspects of the embodiments of the invention. Computer readable programinstructions for carrying out operations of the embodiments of the invention may be, for example,assembly language or either source code or object code written in any combination of one or moreprogramming languages. 50. 50. 50. id="p-50" id="p-50"

[0050] Various program code described herein may be identified based upon theapplication within that it is implemented in specific embodiments of the invention. However, itshould be appreciated that any particular program nomenclature that follows is used merely forconvenience, and thus the invention should not be limited to use solely in any specific applicationidentified and/or implied by such nomenclature. Furthermore, given the generally endless numberof manners in which computer programs may be organized into routines, procedures, methods,modules, objects, and the like, as well as the various manners in which program functionality maybe allocated among various software layers that are resident within a typical computer (e.g.,operating systems, libraries, API's, applications, applets, etc.), it should be appreciated that theembodiments of the invention are not limited to the specific organization and allocation of program functionality described herein. 51. 51. 51. id="p-51" id="p-51"

[0051] The program code embodied in any of the applications/modules described herein iscapable of being individually or collectively distributed as a program product in a variety ofdifferent forms. In particular, the program code may be distributed using a computer readablestorage medium having computer readable program instructions thereon for causing a processorto carry out aspects of the embodiments of the invention. 52. 52. 52. id="p-52" id="p-52"

[0052] Computer readable storage media, Which is inherently non-transitory, may includevolatile and non-volatile, and removable and non-removable tangible media implemented in anymethod or technology for storage of information, such as computer-readable instructions, datastructures, program modules, or other data. Computer readable storage media may further includeRAM, ROM, erasable programmable read-only memory (EPROM), electrically erasableprogrammable read-only memory (EEPROM), ﬂash memory or other solid state memorytechnology, portable compact disc read-only memory (CD-ROM), or other optical storage,magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to store the desired information and Which can be read by acomputer. A computer readable storage medium should not be construed as transitory signals perse (e.g., radio Waves or other propagating electromagnetic Waves, electromagnetic Wavespropagating through a transmission media such as a Waveguide, or electrical signals transmittedthrough a Wire). Computer readable program instructions may be doWnloaded to a computer,another type of programmable data processing apparatus, or another device from a computerreadable storage medium or to an external computer or external storage device via a network.[0053] Computer readable program instructions stored in a computer readable mediummay be used to direct a computer, other types of programmable data processing apparatus, or otherdevices to function in a particular manner, such that the instructions stored in the computerreadable medium produce an article of manufacture including instructions that implement thefunctions, acts, and/or operations specified in the ﬂowcharts, sequence diagrams, and/or blockdiagrams. The computer program instructions may be provided to one or more processors of ageneral purpose computer, a special purpose computer, or other programmable data processingapparatus to produce a machine, such that the instructions, Which execute via the one or moreprocessors, cause a series of computations to be performed to implement the functions, acts, and/or operations specified in the ﬂowcharts, sequence diagrams, and/or block diagrams. 16 54. 54. 54. id="p-54" id="p-54"

[0054] In certain alternative embodiments, the functions, acts, and/or operations specifiedin the ﬂowcharts, sequence diagrams, and/or block diagrams may be re-ordered, processed serially,and/or processed concurrently consistent with embodiments of the invention. Moreover, any ofthe ﬂowcharts, sequence diagrams, and/or block diagrams may include more or fewer blocks thanthose illustrated consistent with embodiments of the invention. 55. 55. 55. id="p-55" id="p-55"

[0055] The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the embodiments of the invention. As usedherein, the singular fonns "a", "an" and "the" are intended to include the plural forms as well,unless the context clearly indicates otherwise. It will be further understood that the terms"comprises" and/or "comprising," when used in this specificatíon, specífy the presence of statedfeatures, integers, steps, operations, elements, and/or components, but do not preclude the presenceor addition of one or more other features, integers, steps, operations, elements, components, and/orgroups thereof. Furthermore, to the extent that the terms “includes”, “having”, “has”, “wit ”,“comprised of”, or variants thereof are used in either the detailed description or the claims, suchterms are intended to be inclusive in a manner similar to the term "comprising". 56. 56. 56. id="p-56" id="p-56"

[0056] While all of the invention has been illustrated by a description of variousembodiments and while these embodiments have been described in considerable detail, it is notthe intention of the Applicant to restrict or in any way limit the scope of the appended claims tosuch detail. Additional advantages and modifications will readily appear to those skilled in theart. The invention in its broader aspects is therefore not limited to the specific details,representative apparatus and method, and illustrative examples shown and described.Accordingly, departures may be made from such details without departing from the spirit or scope of the Applicant°s general inventive concept. 17

Claims

What is claimed is:

1. l. A method for determining a velocity of a vehicle including a sensor ring coupledto and rotatable With a propulsion component of the vehicle and a rotation sensor proximate thesensor ring that generates signals corresponding to rotation of the sensor ring, the methodcomprising the steps of: generating, by the rotation sensor, a first signal and a second signal each corresponding toa rotation of the sensor ring caused by a rotation of the propulsion component, at least one of thefirst signal or the second signal including distortion; constructing a third signal from the first signal; generating a fourth signal by performance of a division operation using the third signal andthe second signal; and determining a speed of the vehicle based on the fourth signal.

2. The method of claim l, Wherein constructing the third signal from the first signal comprises applying a phase shift to the first signal that aligns the first signal With the second signal.

3. The method of claim 2, Wherein the phase shift is ninety degrees.

4. The method of any one of claims 1-3, Wherein determining the speed of the vehiclebased on the fourth signal comprises:deterrnining a value of the fourth signal When the first signal corresponds to a predefinedangle; anddetermining the speed of the vehicle based on the value.

5. The method of claim 4, Wherein the predefined angle is ninety degrees.

6. The method of claims 4 or 5, Wherein determining the speed of the vehicle based on the value comprises accessing a stored lookup table that associates the value With the speed.

7. The method of any one of claims 4-6, further comprising determining a moving direction of the vehicle based on the value.

8. The method of claim 7, Wherein determining the moving direction of the vehiclebased on the value comprises:determining a characteristic of the first signal When the fourth signal equals the value; and determining the moving direction of the vehicle based on the characteristic.

9. The method of claim 8, Wherein the characteristic is Whether the first signal is increasing or decreasing when the fourth signal equals the value.

10. The method of any one of claims 1-9, Wherein determining the speed of the vehiclebased on the fourth signal comprises:determining a peak value of the fourth signal; and determining the speed of the vehicle based on the peak value of the fourth signal.

11. The method of any one of claims 1-10, Wherein generating the fourth signal byperformance of the division operation using the third signal and the second signal comprises:biasing the third signal and the second signal by a predefined value; and dividing the biased third signal and the biased second signal.

12. A method for determining a velocity of a vehicle including a sensor ring coupledto and rotatable With a propulsion component of the vehicle and a rotation sensor proximate thesensor ring that generates signals corresponding to rotation of the sensor ring, the methodcomprising the steps of: generating, by the rotation sensor, a first signal and a second signal each corresponding toa rotation of the sensor ring caused by a rotation of the propulsion component, at least one of thefirst signal or the second signal including distortion; constructing a third signal from the first signal; generating a fourth signal by performance of a division operation of the third signal and the second signal; anddeterrnining a moving direction of the vehicle based on the fourth signal.

13. A Velocity measurement system of a vehicle, the system comprising: a sensor ring coupled to and rotatable With a propulsion component of the vehicle; a rotation sensor proximate the sensor ring that, responsive to a rotation of the sensor ring,generates a first signal and a second signal each corresponding to the rotation of the sensor ring,at least one of the first signal or second signal including distortion; and a controller operatively coupled to the rotation sensor and configured to: construct a third signal from the first signal;generate a fourth signal by performance of a division operation using the thirdsignal and the second signal; and determine a speed of the vehicle based on the fourth signal.

14. The system of claim 13, Wherein the controller is configured to construct the thirdsignal from the first signal by being configured to apply a phase shift to the first signal that alignsthe first signal With the second signal.

15. The system of claim 14, Wherein the phase shift is ninety degrees.

16. The system of any one of claims 13-15, Wherein the controller is configured todetermine the speed of the vehicle based on the fourth signal by being configured to: determine a value of the fourth signal When the first signal corresponds to a predefinedangle; and determine the speed of the vehicle based on the value.

17. The system of claim 16, Wherein the predefined angle is ninety degrees.

18. The system of claims 16 or 17, Wherein the controller is configured to determine the speed of the vehicle based on the value by being configured to access a stored lookup table that associates the value With the speed.

19. The system of any one of claims 16-18, Wherein the controller is configured to determine a moving direction of the vehicle based on the value.

20. The system of claim 19, Wherein the controller is configured to determine themoving direction of the vehicle based on the value by being configured to:determine a characteristic of the first signal When the fourth signal equals the value; and determine the moving direction of the vehicle based on the characteristic.

21. The system of claim 20, Wherein the characteristic is Whether the first signal is increasing or decreasing when the fourth signal equals the value.

22. The system of any one of claims 13-21, Wherein the controller is configured todetermine the speed of the vehicle based on the fourth signal by being configured to:determine a peak value of the fourth signal; and determine the speed of the vehicle based on the peak value of the fourth signal.

23. The system of any one of claims 13-22, Wherein the controller is configured togenerate the fourth signal by performance of the division operation using the third signal and thesecond signal by being configured to: bias the third signal and the second signal by a predefined value; and divide the biased third signal and the biased second signal.

24. A velocity measurement system of a vehicle, the system comprising: a sensor ring coupled to and rotatable With a propulsion component of the vehicle; a rotation sensor proximate the sensor ring that, responsive to a rotation of the sensor ring,generates a first signal and a second signal each corresponding to the rotation of the sensor ring,at least one of the first signal or the second signal including distortion; and a controller operatively coupled to the rotation sensor and configured to: construct a third signal from the first signal;generate a fourth signal by performance of a division operation using the third signal and the second signal; anddetermine a moving direction of the vehicle based on the fourth signal. 22