Embodiment
[0023] example of the present invention comprises inductive position sensor, and it is suitable for use as the accelerator pedal position detecting device in the motor vehicle or the detecting device of other loose impediment position.In representative example, this sensor comprises transmitter coil and receiver coil, and they all are formed at above the printed circuit board (PCB) by printed circuit technique.(for example, pass through ac current source) when transmitter coil is energized, the induction between transmitter coil and receiver coil is coupling in induction generation receiver signal in the receiver coil.The coupler component that is connected to loose impediment is spatially revised the induction coupling between transmitter coil and the receiver coil, allows receiver signal to be used to seek the position of loose impediment.
[0024] inductive position sensor of describing uses transmitter coil (being sometimes referred to as drive coil), receiver coil (or pickup coil) and the conducting element by the alternating current source power supply, described receiver coil is used to respond the time-varying magnetic field that is produced by transmitter coil, produce induced signal, described conducting element is positioned near the described coil, thereby make described time-varying magnetic field in coupler component, produce eddy current, the electric current that this coupler component correction is responded in receiver, this electric current are the function of coupler element position.
[0025] coupler component is connected to movably part, the gas pedal of motor vehicle for example, and what will measure is the position of this part, the angle of coupling mechanism (or rotation) position is exactly the function of the position of throttle element like this.Thus, responding to the voltage that produces in receiver or the pickup coil changes; By detecting the voltage that is received, just can determine the position of coupler component, thereby can determine the position of gas pedal.This signal can be used to control the speed of vehicle motor.
[0026] example of the present invention comprises receiver coil, it has the part of twining in the opposite direction, for example the first of receiver coil is counterclockwise to twine, and second portion twines in a clockwise direction, these two parts preferably have different spatial dimension (that is, not overlapping fully).Term first loop structure and second loop structure are used to such part.From the receiver signal of such receiver coil will be not only to the amplitude sensitivity of coupling of the flux between receiver coil and the transmitter coil or magnetic flux coupling (flux coupling), but also space distribution sensitivity to coming from transmitter coil and passing the magnetic flux line (flux line) of receiver coil.
Common sensor example
[0027] the inductive position sensor example comprises the transmitter coil and the receiver coil of the ac current source that is connected to excitation.Described transmitter coil and receiver coil are supported by same printed circuit board (PCB), and both are above different layers coplane or that be positioned at same plate substantially.It is supported that moveable coupler element is adjacent to this plate, and revise the induction coupling between transmitter coil and the receiver coil.In an example, coupler component rotates around turning axle, and this turning axle can be one of transmitter coil and receiver coil or both central shafts.Coupler element position is revised the amplitude by the receiver signal of described transmitter coil induction by revising the induction coupling between transmitter coil and the receiver coil.
[0028] in sensor example as described above, the amplitude of receiver signal still is the function in the slit (gap) between coupler component and the printed circuit board (PCB), and this slit changes to a certain degree inherently with the manufacturing situation.In order to proofread and correct the variation that receiver signal is caused by described slit and other common-mode signal (for example variation of driver or supply voltage, EMC and temperature variation), also can use reference coil, for example be formed at the reference coil above the same printed circuit board (PCB) of transmitter coil and receiver coil.Reference coil receives and the same signal of receiver coil, but its mode that is configured makes reference signal insensitive for the variation of the position of rotation of coupler component.Signal Regulation or treatment circuit receive receiver signal and reference signal, and form rate signal, and this rate signal is represented the ratio of receiver signal and reference signal.This rate signal is relevant with coupler element position, but in rational variation range, it changes with the slit and other common mode factors has nothing to do substantially, and this will further discuss below.
[0029] configurable printed circuit board (PCB) makes it have the input that is used for electric energy, and the output that is used to provide receiver signal and reference signal.Replacedly, the electronic circuit on the circuit board can be used to produce the rate signal as the ratio of receiver signal and reference signal.Can use signal processing circuit with receiver signal divided by reference signal, be not that the signal of function of coupler element position changes to remove basically.
[0030] induction pick-up of example comprises transmitter coil (it also can be called as drive coil), receiver coil and coupler component according to the present invention.Described transmitter coil is connected to the ac current source such as Collpitts oscillator (Colpitts Oscillator), described coupler component is supported with physical relation or entity relationship (physical relationship) with respect to described transmitter coil and receiver coil, makes the position influence of coupler component arrive the intensity of the induction coupling between transmitter coil and the receiving coil.The receiver signal that is provided by receiver coil can be relevant with the position of coupler component.
Transmitter coil
[0031] transmitter coil can be the one or more loops in traditional circular coil design, perhaps can use other structure.The transmitter coil that is also referred to as drive coil is encouraged by alternating current.This driving source or alternating current may be such as Collpitts oscillator such electro coupled oscillator or other electro coupled oscillator.
[0032] when transmitter coil was subjected to the electric energy excitation, it gave off electromagnetic radiation.Transmitter coil and any other near have the induction coupling between the coil, it induces signal in this coil.
[0033] transmitter coil can be the circular coil with a circle or multiturn.Provide pumping signal by ac current source for this transmitter coil.Induction between transmitter coil and the receiver coil is coupling in and produces receiver signal in the receiver coil.
Coupler component
[0034] coupling of the induction between coupler component correction transmitter coil and the receiver coil.In example of the present invention, coupler component does not need between transmitter coil and receiver coil, although it can be provided with like this as easy configuration.In addition, in example of the present invention, coupler component does not need to revise the whole flux couplings between transmitter coil and the receiver coil, but can only revise the space distribution of flux coupling.If coupler component is a conductive pads, then it also is called as eddy-current disc (eddy plate).
[0035] coupler component can be a conducting element, it has smooth substantially shape and can comprise one or more limbs (lobe) that radially extend, and this conducting element is supported so that it rotates the parallel and close printed circuit board (PCB) of its limb of while (one or more) around the center line that transmits and receives coil.The structure of limb or shape may extremely depend on the structure of receiver coil.
[0036] coupler component is connected to, or otherwise mechanically is coupled to movably object, so the position of rotation of this coupler component is the function of this loose impediment position.The structure of receiver coil as further discussing hereinafter, can be such: it makes voltage produce in output place of receiver coil, and this voltage is the function of coupler element position.
[0037] in the vehicle application example, coupler component is connected to, or otherwise is mechanical coupling to movably pedal arm or other vehicle control arm, so the position of rotation of coupler component is the function of the position of this moveable arm.
[0038] coupler component can have the initial position with respect to receiver coil, in this position receiver signal minimum.Along with coupler component moves from its initial position, it just revises the induction coupling between the transmitter coil and first and second loop structures.In example of the present invention, in coupler component initial configuration or structure (configuration), first and second signals have close amplitude and opposite phases, so these two signals are tending towards cancelling each other out.When coupler component moved, the induction coupling between the transmitter coil and first loop structure increased, and the coupling of the induction between the transmitter coil and second loop structure simultaneously reduces.Along with the difference increase of the amplitude between first and second signals, receiver signal strengthens.
Receiver coil
[0039] term " receiver signal " generally can be used to be illustrated in the signal that induction produces in the receiver coil, also can represent the signal based on any adjusting of the signal of induction generation in the receiver coil.
[0040] in the example that is discussed below, an independent receiver signal is provided by receiver coil, and this receiver signal can comprise from the contribution that is formed at first and second signals in first and second loop structures.Receiver coil can comprise first loop structure and second loop structure, and they provide first and second signals respectively.Then, receiver signal is certain combination of described first and second signals.
[0041] for example, first and second loop structures can be configured, and have the signal of opposite phase with generation, and receiver signal is the combination of first and second signals, and therefore when first and second signals had close amplitude, receiver signal had minimum value.Receiver signal also can be referred to as difference signal, and this is because the amplitude of receiver signal is the poor of induction produces in induction produces in first loop structure first signal amplitude and second loop structure secondary signal amplitude.
[0042] in other examples of the present invention, receiver coil can provide first and second signals of separation to electronic circuit from the loop structure that separates, is used for handling.
[0043] first and second loop structures of receiver coil can be configured, and with for the given magnetic flux change of passing receiver coil, provide first and second voltages of opposite polarity.Configurable receiver coil is so that first and second signals are tending towards cancelling out each other under the situation that does not have coupler component.Described coupler component also can have zero position, stops comparably that at this position coupler component the flux of first loop structure and second loop structure transmits, and therefore first signal and secondary signal cancel each other out effectively.When coupler component with respect to initial position when first direction moves, it is more to have stopped that induction produces magnetic flux of secondary signal, has simultaneously lessly stopped that induction produces the magnetic flux of first signal.Therefore, the amplitude of first signal increases, and the amplitude of secondary signal reduces, and receiver signal increases on amplitude.This coupler component can also move in second direction, and the amplitude of secondary signal increases on this direction, and the amplitude of first signal reduces.
Reference coil
[0044] in further example of the present invention, a kind of reference coil that can be called as differential analogies (dummy) sometimes is provided, this reference coil provides the reference signal of the location independent of basic and coupler component.Yet this reference signal is vulnerable to the influence of same factors, and these identical factors generally can be called as common mode factors, and it influences the intensity of receiver signal.Common mode factors can comprise following one or more: the receiver noise that the coupling mechanism slit between coupler component and transmitter (or receiver) coil, the variation that is applied to the driving voltage of transmitter coil, ambient electromagnetic field induction produce, temperature variation or the like.
[0045] the adjustable induction pick-up is so that the output of this sensor has canonical form, and the model change during itself and sensor are made is irrelevant.In automated system, coupling mechanism slit between coil (it can be supported on above the printed circuit board (PCB)) and the coupler component (it is connected to accelerator pedal) affects the signal that induction produces in the receiver coil consumingly, and the accurate control to this coupling mechanism slit is difficult in large-scale production process.Yet calibration process may be error source and be expensive.
[0046] traditional induction pick-up need be such as the broad calibration curve of the common mode factors of temperature.For example, traditional induction pick-up can comprise temperature sensor, temperature correction factor look-up table, and the circuit of realizing temperature correction.The unreliability that the rate signal of use example according to the present invention can be avoided many these extra complexities and be associated.
[0047] by the recently definite rate signal with receiver signal and reference signal, the influence of common mode factors can greatly be suppressed, so rate signal is just irrelevant with common mode factors basically, but also relevant with coupler locations.This rate signal can be determined by mimic channel.
[0048] reference coil can be similar to a certain extent with receiver coil, but can be arranged such that by transmitter coil in reference coil, respond to the reference voltage that produces basically with the location independent of coupler component.Hereinafter example will be discussed further, for example in the discussion relevant with Fig. 8.Induction coupling between transmitter coil and the reference coil is subjected to the influence of similar common mode factors, just as the induction coupling that influences between transmitter coil and the receiver coil.These factors comprise coupler component and support transmitter coil and the printed circuit board (PCB) of receiver coil between the slit, perhaps coupler component and transmitter coil or other support the slit between the structure of transmitter coil.
[0049] other common mode factors that can use reference coil to obtain to compensate comprise because the receiver signal that variation caused of the alternating current power supply of transmitter coil changes, by from the variation that induced voltage caused of the irrelevant stray electromagnetic signals of sensor operation, temperature variation or the like.
[0050] in vehicle was used, coupler component can be mechanically connected to gas pedal, so the position of rotation of coupler component is the function of accelerator pedal position.The application of example of the present invention comprises such structure: wherein coupler component is connected to the removable part of its position of needs monitoring, and transmitter coil, receiver coil and support circuit are arranged on the substrate such as printed circuit board (PCB).Described substrate is held by shell or other structure that removable part moves therein, and perhaps described substrate is fixed near shell that removable part moves therein or other structure.For example, removable part can be a pedal, and configurable pedal shell is to hold printed circuit board (PCB), printed coil on this printed circuit board (PCB).Product component changes and may cause the variation in the slit between coupler component and the printed circuit board (PCB), and the use of reference coil allows this manufacturing changed and compensate, and does not need a large amount of calibration processes.
[0051] coil arrangement can be taked various ways.For example, coil can twine with the magnetic pole (pole) of different numbers, and they will influence the position resolution of sensor.The configuring receiver coil is so that the amplitude of the position modulation receiver signal of coupler component.If use reference coil, then configurable this reference coil is so that the position of reference signal and coupler component is irrelevant substantially, also the position with coupler component is relevant for the rate signal that so just feasible employing reference signal and receiver signal obtain, but irrelevant substantially with the factor such as temperature.
[0052] in an example, transmitter coil, receiver coil, and reference coil all is printed on the printed circuit board (PCB), this printed circuit board (PCB) can be a multilayer board.In other example, described coil can be formed on the separated structures.
[0053] Fig. 1 illustrates a kind of transmitter and receiver winding of form with planimetric map.Also can form such as the optional reference coil of graphic extension schematically in Fig. 4, and this reference coil and the transmitter and receiver coil overlaid that is positioned at above the same printed circuit board (PCB).
[0054] transmitter coil 12 is made up of the loop of one or more stamps, and described loop has semicircular shape substantially, and is formed on above the printed circuit board (PCB) (PCB) 10.Can be formed at oscillator 14 on the same PCB is connected to transmitter coil and provides alternating current (pumping signal) for this transmitter coil, produce the electromagnetic field that alternately changes, this electromagnetic field is coupling in to respond in other contiguous coil by induction subsequently and produces signal.
[0055] receiver coil 16 has outer perimeter, and it is preferably located within the zone that is limited by transmitter coil 12.In this example, receiver coil comprises first and second loop structure 16a and the 16b, and it is fan-shaped that each described structure represents that all about 90 of a border circular areas is spent.Two loop 16a are connected 18 with 16b by commutation and link together, and are not electrically connected between the electric conductor that intersects.Receiver coil is configured, if so that electric current flows in receiver coil 16, then electric current will and be distinguished reversed flow among the 16b at district 16a.As graphic extension among Fig. 1, when clockwise electric current flowed in district 16a, electric current flowed in district 16b counterclockwise.
[0056] therefore, receiver coil comprises first loop and second loop, and (that is, with counterclockwise, vice versa clockwise) twined with opposite direction in described loop, and described loop has different spatial dimensions.In the example of Fig. 1 graphic extension, first and second loops have non-overlapped spatial dimension, and some are overlapping although have in other example.
[0057] by using moveable coupler element to revise the space distribution of the flux coupling between transmitter coil and receiver coil, receiver signal changes in the mode relevant with the position of coupler component.
[0058] in this example, first loop provides first signal and second loop that secondary signal is provided, first voltage produces by the induction inductive coupling with transmitter coil in this example, and second voltage is produced by the induction inductive coupling between second loop and the transmitter coil.Since first and second loops have on the contrary to winding (that is, clockwise and counterclockwise, vice versa), therefore first and second voltages are opposite.
[0059] if the coupling of the induction between transmitter and two loops is similarly, the voltage of then responding to generation will be tending towards opposite each other, and receiver signal will be minimum value, and this minimum value may be 0.
[0060] Fig. 1 has shown two loop structures, and it is arranged as the layout of about semicircle.In linear position sensor, this loop structure can be arranged in linear the layout.In addition, any amount of successive loops structure can be arranged.
[0061] Fig. 2 has shown coupler component 20, and it is made with conductive material, and is basically parallel near circuit board 10 and supported circuit board 10.Contact Fig. 1, this figure is a top view, plate wherein is shown as horizontal sectional drawing.Coupler component has reduced the induction coupling between transmitter coil and the receiver coil.Transmitter coil 10 and receiver coil 16 have been shown among this figure.Coupler component can for example be the metal dish of self-supporting, or is supported on the metal film on the substrate, for example is formed on the metal film in the copper coated circuit board.
[0062] Fig. 3 has shown coupler component 20 with planimetric map, and the transmitter coil 12 and the receiver coil 16 that are connected with oscillator 14 have covered circuit board 10.Coupler component 20 rotates around pivot 22 in the plane that is basically parallel to plane, transmitter and receiver coil place by link 24.
[0063] if coupler component is with respect in the middle of two loops are positioned at, then it approximately stops flux coupling between transmitter coil and two loops with the degree that equates.Like this, in each loop, respond to the voltage that produces approximately equal but reverse (equivalently, the alternating voltage that induction produces is an out-phase), so receiver signal will be a minimum value.But, when coupler component rotates around pivot 22, when for example turning clockwise, it will stop that morely the flux between the transmitter coil and second loop (on the right side of Fig. 1) is coupled, and will less stop the flux coupling between transmitter coil and first loop (in the left side of Fig. 1).Like this, in first loop, respond to the voltage magnitude that produces and greatly to surpass the voltage magnitude of in second loop, responding to generation, thereby receiver signal will increase.
[0064] another of this structure is characterised in that its sense of rotation for coupler component is responsive, if for example the phase place of receiver signal is determined.The circuit that is associated for example can be converted to anti-phase alternating voltage the DC voltage with respect to the contrary sign of defined ground voltage.
[0065] for example, coupler component 20 can be the fan-shaped forms of basic 90 degree, thus its can cover at any time one of receiver coil 16a or 16b or transmitter loop 12 basic half.
[0066] Fig. 3 can use corresponding to certain, and coupler component 20 can use pedal arm (pivot able pedal arm) to drive by the pivot of accelerator pedal of automobile therein, so the angle of coupler component 20 (or rotation) position is exactly the function of pedal position.In this application, receiver signal is relevant with pedal position, and can be used to control engine speed.
[0067] Fig. 4 illustrates a reference coil, and it can overlap above the circuit board 10 with symmetric relation together with coil 12 and 16.This reference coil is supported by identical circuit board as other coil, and may be positioned within the multilayer circuit board.
[0068] reference coil 26 has the structure of receiver coil of being similar to 16, but it only uses an independent loop.Therefore, the angle of coupler component 20 (rotation) position does not have influence on the electric current that reference coil 26 internal inductions produce.Coupler component 20 roughly covers half of reference coil, and is irrelevant with the position of rotation of reference coil (within the certain angle scope), and the basic position of rotation same and coupling mechanism 20 of the amplitude of the electric current that induction produces in coil 26 is irrelevant.Yet, the variation that changes, produces by temperature variation such as electromagnetic interference (EMI), driving voltage, and the gap position between coupler component 20 and the printed circuit board (PCB) 10 changes such common-mode signal and will have influence on the voltage that induction produces in the reference coil 26, and the mode of influence is identical with the mode that these common-mode signals influences the voltage of responding to generation in the receiver coil 14.
[0069] Fig. 5 is the rough schematic view of electronic circuit, and this circuit can be incorporated the induction pick-up of the example according to the present invention into.Provide this electronic circuit to be used for the processes sensor output signal, for example to be used for the control signal of vehicle motor.
[0070] Zhen Dang ac current source 14 is coupled to drive coil 12.Coupling mechanism 20 is illustrated as for simplicity at this and is arranged between drive coil 12 and receiver coil 16 and the reference coil 26.The output of receiver coil 16 and reference coil 26 is transmitted by amplifier 44 and 46, and is provided for a pair of multiplier 48 and 50 respectively.Multiplier 48 and 50 is gone back second input of reception oscillator signal 14 as them, and they play the effect of detuner.Demodulation multiplier 48 and 50 output are offered a pair of low-pass filter (LPF) 52 and 54 respectively.The output of low-pass filter is delivered to divider 56.
[0071] low-pass filter extracts constant reference coil signal and roughly is the signal of coupling mechanism 24 function of position from wave filter 52.By divider 56 carry out with of the operation of coupling mechanism coherent signal divided by the reference coil signal, roughly removed common mode variations, for example the signal level variation that causes owing to the variation of the slit between coupler component and the printed circuit board (PCB), driver change in voltage, electronic noise or the like.
[0072] output of divider 56 has constituted control signal 58.In the application of automobile, this signal can be used to control the rotating speed of engine.Can increase other circuit and signal gain is adjusted into 0, and adjust the upper and lower bound of the clamp level of output signal at the predetermined point place.
[0073] in Fig. 1, transmitter coil is shown as and comprises single-turn circular coil.Yet, also can use multiturn.Similarly, first and second loop structures of receiver coil can comprise multiturn.
[0074] in exemplary automobile was used, gas pedal was mechanically coupled to coupler component, so that the position of pedal position control coupler component.For example, coupler component can rotate in the circuit board plane of the transmitter and receiver coil that contains electronic circuit and support.
[0075] Fig. 6 has shown another example of induction pick-up, and it comprises rotating disc 60, and this rotating disc 60 has a plurality of conducting strips (patch), and for example coupler component 62.Induction pick-up also comprises receiver coil 64, reference coil 66 and receiver coil 68.Reference coil more clearly illustrates in Fig. 8.
[0076] receiver coil is by the alternating current source forcing that is connected to receiver coil terminal 86 and 88.The receiver coil of excitation generates an electromagnetic field, and this electromagnetic field is coupling in induction generation signal in reference coil 66 and the receiver coil 68 by induction.The induction coupling between the two of transmitter coil and reference coil and signal coil is by revising (minimizing) such as the coupler component of coupler component 62.Yet the induction coupling between transmitter coil and reference coil is also insensitive for the angle position of the coupling mechanism of rotation.On the contrary, receiver signal is responsive for the angle position of rotating disc 60, therefore just the angle position with rotary coupler is relevant for the ratio of receiver signal and reference signal, and the common mode factors (for example, the slit between transmitter coil and the rotating disc) of having passed through simultaneously also as indicated above is proofreaied and correct.Receiver signal obtains between receiver coil terminal 70 and 72.
[0077] outer perimeter of receiver coil comprises continuous segmentation, for example 78,74 and 76, and continuous therein segmentation is alternately as the part of first loop structure or second loop structure.For example, outer segmentation 74 is parts of the loop structure identical with interior segmentation 82, it links to each other by radial spokes 80, and described outer segmentation 74 and interior segmentation 82 boths are parts of first loop structure, and outer segmentation 76,78 and interior segmentation 84 are parts of second loop structure.As illustrated, as second loop structure part such as 80 radial spokes after hidden second radial spokes arranged, this hidden spoke is the part of first loop structure.Two loop structures connect interconnection by commutation, thereby the secondary signal in first signal in first loop structure and second loop structure is opposite each other, and if identical to each the induction coupling in two loops, these two signals can be offset.Described counteracting for example takes place when the coupling mechanism of rotation is removed.In position sensor applications, if the coupler component of rotation can move on to certain position, the induction of loop structure coupling reduces in this position to one, and increases to the induction coupling of another loop structure, then changes receiver signal with the form relevant with coupler element position.
[0078] in this example, first loop structure comprises a plurality of limbs that radially extend, and described limb is formed by interior segmentation, radial spokes, outer segmentation, radial spokes, interior segmentation or the like.The radially limb of first and second loop structures is being shown within the receiver coil of Fig. 6 alternately.In addition, as be presented in the example of Fig. 6, coupler component is a segmentation, and its angular width doubles the angular width of the radially limb of first or second loop structure.As shown, receiver coil is whole substantially forms by radial conductor or with the element of radial direction quadrature.
[0079] Fig. 7 is the rough schematic view according to the induction pick-up of another example of the present invention.This sensor comprises receiver coil (hereinafter discussing), reference coil 104, rotary coupler 103 and transmitter coil 100, and described rotary coupler 103 has the electric-conductive coupler element such as 102.
[0080] receiver coil comprises first and second loop structures 106 and 108 respectively.These loop structures are that the convenience of graphic extension is separated.Yet if desired, receiver coil can comprise the loop structure of this separation.The actual limb that comprises such as 110 and 112 of the receiver coil that is illustrated in the right side, it has mark S and N alternately.This nomenclature is indicated first and second loop structures, and they are interconnected, and will flow through adjacent limb as clockwise electric current so flow through the counterclockwise electric current of a limb, and the magnetic field that induction produces alternating direction in the limb that radially extends continuously.In other words, when two loop structures were exposed in the electromagnetic field that comes self-energizing transmitter coil, the connection of intersection can be used to produce opposite induced voltage in receiver coil.
[0081] rotary coupler 102 has been revised the induction coupling between two loop structures of transmitter coil 100 and receiver coil around the rotation of axle 103, but does not influence the induction coupling between transmitter coil and the reference coil 104 significantly.
[0082] Fig. 8 has shown the example reference loop construction, and it has outer circle 120 and two interior circles.To discuss in more detail in other place of this instructions and use reference coil to come the influence of basic neutralisation common mode factors.122 two interior linkage are received outer circle by being connected with a joggle, this is connected with a joggle and 122 has been avoided electrically contacting between the electric conductor.Reference signal is the induced voltage that obtains at 124 places.
[0083] Fig. 9 electric current of further illustrating two circles of the single turn that passes external loop 126 and inner looping 128 flows.Reference signal will be the reference voltage output at 130 places, and it is the opposite induced voltage sum within inner looping and the external loop.
[0084] if reference coil is connected to current source, then the direction of current along interior circle and outer circle will have opposite direction, and will be for example illustrated as the arrow among Fig. 9: the outer circle clockwise direction in edge, and counterclockwise along interior circle.
[0085] in this example, reference coil has outer diameter D
oAnd inside diameter D
iThe general topology of reference coil can make and be output as 0 when removing coupling mechanism, and this can realize by disposing reference coil with following relation: n
iD
i 2=n
oD
o 2, n wherein
iBe the number of turn of interior circle, n
oIt is the number of turn of outer circle.In the example of Fig. 8 and 9, reference coil has an outer circle and two interior circles.
[0086] the example reference coil is designed to E-Gas control application.In an example, the internal diameter of reference coil (2 circle) is 17.7mm, and external diameter (1 circle) is 25mm.In another example, the internal diameter of reference coil (3 circle) is 14.4mm, and external diameter (1 circle) is 25mm.
[0087] reference signal can be considered to two electric currents and: electric current is produced by a coil that comprises interior circle (one or more), and opposite electric current is by second coil generation that comprises outer circle (one or more).Coupler component has stopped the part induction coupling to the outer circle of this second coil, has caused composite signal.Yet, the location independent of the basic and coupler component of this composite signal.
[0088] but the design reference coil so that the induced signal in the radial component of loop construction is cancelled.
[0089] Figure 10 A illustrates coupler component 140, and it for example can be supported on the rotating disc 142.Coupler component has interior circumference, circular arc and has external coupler diameter D
COOuter perimeter, described circular arc has intercoupler diameter D
Ci, this diameter is corresponding to the twice of the arc radius of measuring from turning axle.
[0090] Figure 10 B illustrates the rough schematic view of receiver coil.Coupler component 140 is facing to the adjacent limb of a pair of receiver coil.In this rough schematic view, and be used to obtain the joint (tap) of receiver voltage in the not shown receiver coil.Outer segmentation 144 and 146 alternately corresponds respectively to the first and second loop structure parts, and the electric current that flows through receiver coil therein flows with opposite direction (clockwise with counterclockwise).If same electric current passes this coil and flows, then direction of current is between the adjacent outer segmentation, also alternately change between adjacent interior segmentation.Radial spokes is corresponding to from the conductor in first loop with from the conductor in second loop, and described conductor from first loop is electric current segmentation outside interior segmentation is carried to, and described conductor from second loop is with opposite direction delivery electric current.Receiver coil has the D of being respectively
RIAnd D
RIThe inner receiver diameter and outer receiver diameter.
[0091] induction pick-up of example comprises the coupler component of Figure 10 A, the receiver coil of Figure 10 B according to the present invention, and has driver diameter D
EThe transmitter coil of a plurality of round circles.In example of the present invention, the intercoupler diameter approximates the inner receiver diameter greatly, and the external coupler diameter approximates the driver diameter greatly, and the driver diameter is greater than (perhaps can approximate greatly) outer receiver diameter.Coupling mechanism, receiver coil and transmitter coil have public central shaft.
[0092] Figure 10 B illustrates and has the concentric interior circumference and the receiver coil of outer perimeter, and each circumference has all comprised crooked conductive section, carried the alternatively, sectionally of electric current in the opposite direction.Receiver coil can comprise the concentric assembly of a plurality of this structures, approximates the internal diameter of next macrostructure greatly than the external diameter of minor structure.In other example, the radial spokes that is shown among Figure 10 B can be a resistive element.
[0093] Figure 11 has shown another graphic extension of receiver coil, and electric current is carried in wherein continuous outer conduction segmentation 150 and 152 in the opposite direction.If electric current passes coil, then continuous limb 154 and 156 produces opposite magnetic field.
[0094] in of the present invention other were used, other mechanical organ can be used to drive.Coupler motion can be certain combination of linear, rotation or one or more direction rotations and linear movement.
[0095] coupler component can be the intrinsic part that will measure the removable part of its position, perhaps can be connected to this removable part, perhaps otherwise by mechanical connection, makes coupler element position relevant with removable part position.
Bipolar transmitter coil
[0096] in other example of the present invention, transmitter coil can be configured to as shown in figure 12.Arrow is represented sense of current in the circulation of alternating current excitation.Transmitter coil has can be referred to as certain bipolar structure, and it has first loop 160 and second loop 162, their interior zone respectively by clockwise and counterclockwise electric current loop around.Like this, two transmitter coil loops have produced the magnetic field with opposite magnetic flux direction.This structure can be described to have two limbs, about 180 degree of each limb.Yet, the limb of more number more, such as 4,6,8 or other number all be operable so that receiver coil produces opposite magnetic flux from different area of space.
[0097] use transmitter coil as shown in figure 12, do not having under the situation of coupler component, the voltage that induction produces in receiver coil (for example can be one or more circular turn in this example) can be configured to 0, and this is owing to cause from the otherwise impact of the flux coupling of two opposite magnetic fields.Yet, can use coupler component optionally to stop magnetic flux from first or second loop, this has caused the receiver signal relevant with coupler locations.The same with other examples discussed above, the space distribution of the flux coupling between coupler component correction transmitter coil and the receiver coil has caused the receiver signal relevant with coupler locations.
[0098] transmitter coil can produce electromagnetic flux, and it has the space distribution of magnetic direction in particular moment, and a coupler component is used for revising this space distribution, makes receiver signal relevant with coupler locations.The coupling of the total flux of amplitude need not change when coupler component moves as a whole.
Other coupler component structure
[0099] coupler component relies on the eddy current that results from the coupler component to stop that the induction between transmitter coil and the receiver coil is coupled, and this eddy current has shielded flux for this receiver coil effectively.Coupler component needs not be plate-like.
[0100] Figure 13 illustrates another kind of possible coupler component example.When the removable part such as pedal moves, coil 184 rotatablely, it has two coupler components of arranging on it, and they are the form of first coupler loop 180 and second coupler loop 182.By the magnetic flux that produces by transmitter coil, can in these rings, produce eddy current, and these eddy current are effectively for receiver coil shields flux, this shielding mode is similar to the conductive pads (conducting plate) of similar size.Therefore, coupler component can be for conductive pads, conductive rings or such as the porose form that pierces other structure of dish wherein, for example reducing weight or to allow fluid, or generally have one or more holes (aperture) but have the dish of at least one conductive perimeter ring by this coupler component.
[0101] be circular rings at transmitter coil, for example as shown in Figure 6, and described coupler component is in the example of some axle rotations, described coupler component can be configured to has circumference, circular arc and outer ring circular arc in this circumference comprises interiorly are connected by radial side with the outer ring circular arc.In this manual, to refer to the central shaft be center geometry for radius and circular arc.The coupler component circumference can be the outward flange of dish, or the route of galvanic circle for example.
Signal Regulation
[0102] Signal Conditioning Equipment and method are described in the applicant's who submitted on April 8th, 2005 associating pending trial U.S. Provisional Patent Application 60/_, _ number in, its title is " SignalConditioning System for Inductive Position Sensor ".
[0103] in example of the present invention, receiver signal is coupled the modulation of device position of components effectively, and reference signal is basic and coupler element position is irrelevant.Multiplying each other of receiver signal and pumping signal (being provided to transmitter coil) followed in the amplification of receiver signal thereafter, following low-pass filtering after this, and these processing can be used to provide receiver signal, and it is the DC voltage relevant with coupler element position.Similarly, reference signal also can be exaggerated and exciter signal multiplies each other, and to be low pass filtering to provide be the reference signal of DC voltage, and this signal changes with the common mode factors that also influences receiver signal.Then, receiver signal obtains rate signal divided by reference signal, and also the position with coupler component is relevant for it, but irrelevant with common mode factors basically.In example of the present invention, multiplication and division steps described in this section are carried out by mimic channel.
[0104] then, aforesaid and also can further be amplified corresponding to the output of 58 analog divider among Fig. 6.The scope of output voltage can be clamped to upper and lower stationary value (plateau value), and amplifier gain is adjusted to obtain the required gradient or slope (angle position is with respect to output voltage).Can use trimmer resistor to adjust gain slope to required numerical value.For example, can use the laser trimming of resistor, burning-off carbon ribbon (carbon strip) perhaps also can use traditional slide rheostat in some applications to obtain required semifixed resistor.In automobile electric gasoline throttle control is used, can during factory calibrated, carry out once this fine setting and regulate.The use of ratio sensing (having used reference coil) has greatly reduced the demand to later calibration adjustments.
[0105] in example of the present invention, whole Signal Regulation can be carried out by mimic channel.Digital signal processor does not need.In other example, rate signal can form by simulation division, but digital circuit is used for signal is exported the upper and lower stationary value that is adjusted to hope.
[0106] output voltage can not exclusively be linearly dependent on the position.The range of linearity that definable can be used is extrapolated to virtual earth (its may (true ground) is negative voltage with respect on the spot).Rate signal can form that (receiver signal+A)/(ratio of reference signal+B), wherein reference signal and receiver signal for example are meant respectively by separating of receiver and reference signal and are in harmonious proportion the DC voltage that low-pass filtering obtains.A and B are owing to the scope supposition in slight nonlinear response is that the linear virtual earth that causes is proofreaied and correct.The width of useable linear range can be determined by position accuracy specification (specification).It is very approaching that correction term A and B are likely, and in some instances, can use the virtual earth of identical numerical value to proofread and correct to A and B.
[0107] can use further calibration steps to regulate lower and upper steady voltage.The discussion of back is relevant with automotive example.Can use idle running steady length (constant of gas pedal under some little pressure (gas pedal) hangs down steady voltage).Constant voltage can be added to output voltage obtaining required gradient position, and this has also regulated the steady length of idle running.Scalable neutral (low steady voltage) for example uses virtual earth to regulate.For example, virtual earth can be with respect to the about 2.5V in ground, chassis, is used for the voltage output range of about 0-5V.The switchable resistor that use is positioned within the ASIC of circuit board top can be realized calibration, and only needs be carried out once during sensor factory makes.
[0108] if use reference coil (or differential analogies) output to compensate common mode factors, example then of the present invention does not need storer, for example, is used for the storer of storing temperature calibration data.
[0109] induction pick-up according to the present invention comprises the non-contact inductive sensor that is used for the automobile application, and it comprises the sensor that uses transmitter winding, receiver winding, rotatable coupling mechanism and tertiary coil.Described transmitter winding encourages by alternating current; Described rotatable coupling mechanism is connected to gas pedal, and its position is relevant with winding, is used for changing the transmitter signal amplitude that induction results from receiving coil; Described tertiary coil receives the signal that is similar to receiver signal, and this signal is basic and the coupling mechanism position of rotation is irrelevant, is used to compensate the slit of signal between coupling mechanism and coil that is received and changes and other common-mode signal.
[0110] other application of the inductive position sensor of example comprises electronics suspention (electronic suspension) control according to the present invention, the vehicle load weight detecting, electric brake control, electric clutch control, hand throttle control, the one or more dimensions accelerometer (for example, move by the relative inertness that detects owing to the object that quickens to cause), electronic driving control (for example, the bearing circle rotation, whether the adjustable and retractable position is suitable, and wheel angle), tyre pressure sensor (for example, detect because the displacement that pressure causes), driftage (yaw), jolt (pitch) and rock (roll) control, seat position detects, and rotational speed (in examples more of the present invention).The engine speed of example (throttle) control comprises the manual control of the control of engine of boat and ship rotating speed, the control of aeroengine rotating speed, any kind vehicle according to the present invention, or the like.
[0111] example of the present invention can be made on little linear scale, such as microscale, for example as the MEM structure, and can be used in microelectronics system, microfluidic control, computer memory drive controlling or the like aspect.
[0112] in other example of the present invention, coupler component can comprise conducting fluid, fluent material or other deformable material.Example of the present invention can be used to determine the distribution of conductive material, for example near the scope of the conductive material of transmitter and receiver coil.
[0113] in other example, reference coil and receiver coil can be integrated in the single structure.Can provide and switch receiver coil and be configured to reference coil, and can return the receiver coil configuration once more.Specific sensor application needs redundant sensor element.Like this, sensor may comprise two or more transmitter coils, receiver coil, and reference coil.
[0114] the present invention's example of being not limited to above illustrate.Example also is not intended to limit scope of the present invention.Method described here, device, complex or the like all are exemplary, and are not intended to as limiting the scope of the invention.It may occur to persons skilled in the art that wherein variation and other use.Scope of the present invention is defined by claims.
[0115] patent of mentioning in this manual, patented claim or be disclosed in this and incorporate this paper by reference into are specifically and individually to indicate with way of reference to incorporate this paper into as each independent file just.Specifically, No. the 60/561st, 065, the U.S. Provisional Patent Application of submitting on April 9th, 2004; Submitted on April 9th, 2004 the 60/561st, No. 007; The 60/__ that submit on April 7th, the 60/589th, No. 192 1 of submitting on August 2nd, 2004, _ _ number, and the 60/__ that submitted on April 8th, 2005, _ _ number, all incorporate this paper at this.
[0116] after the invention of having described me, my claimed appended claim restricted portion.