Patent Application
20090091313
The present invention relates generally to the field of position sensors, and more particularly relates to an inductive position sensor with integrated light emitting diode (LED) indicators.
Automotive vehicles equipped with an automatic transmission include a selector lever or shifter that allows the driver of the vehicle to engage the transmission in one of a series of predetermined transmission settings, including park, reverse, neutral, and one or more drive settings. The drive setting may include normal drive, overdrive and low gear settings. A visual indication system is also provided for indicating the selected transmission setting. Such systems typically include alphanumerical characters (e.g., P, R, N, D, L, OD, 3, 2, etc.) which are arranged alongside the travel path of the gear shifter selector lever, and a position indicator located adjacent the alphanumerical signs or symbols to provide a visual indication of the selected transmission setting. One type of visual indicator commonly used in association with automatic transmissions includes a mechanical pointer that is fixed with respect to the selector lever, and which is variably positioned adjacent the alphanumerical signs or symbols corresponding to the selected transmission settings. Other types of visual indicators include a series of lights positioned adjacent the alphanumerical signs or symbols, wherein the light located adjacent the alphanumerical sign or symbol which corresponds to the selected transmission setting is illuminated. Additionally, various types of position sensors are sometimes used to provide an electronic signal that corresponds to the physical position of the gear shifter selector lever and/or the selected transmission setting. Such position sensors include, for example, limit switches, microswitches and proximity sensors. In the past, the visual indication and position sensing systems have been provided separately by way of individual system components. However, providing visual indication and position sensing capabilities via separates system components tends to increase manufacturing and assembly costs. Additionally, particular care must be taken to avoid electrical or mechanical interference between the visual indication system and the position sensing system.
Thus, there remains a need for an improved position sensing system for use in association with a mechanical transmission. The present invention satisfies this need and provides other benefits and advantages in a novel and unobvious manner.
The present invention generally relates to an inductive position sensor with integrated light emitting diode (LED) indicators, and more specifically relates to a position sensing and visual indication system for use in association with a mechanical transmission.
In one form of the present invention, the system includes a transmission gear shifter mechanism including a gear selector lever movable between a plurality of predetermined shift positions corresponding to respective transmission settings, an inductive position sensor configured to sense a relative shift position of the gear selector lever associated with a selected one of the transmission settings, and a visual indicator configured to provide a visually perceptible indication of the selected transmission setting.
In one embodiment, the inductive position sensor includes a first inductive sensor element mechanically coupled to the selector lever, a second inductive sensor element electromagnetically coupled to the first sensor element, and inductive position sensor circuitry associated integrated onto a primary circuit board, wherein movement of the gear selector lever correspondingly displaces the first sensor element relative to the second sensor element, and with the first and second sensor elements cooperating to generate a sensor output signal corresponding to a position of the first sensor element relative to the second sensor element which in turn corresponds to the shift position of the gear selector lever associated with the selected transmission setting.
In another embodiment, the visual indicator includes an indicator panel including alphanumeric characters positioned adjacent corresponding ones of the predetermined shift positions and which designate respective transmission settings, a plurality of light emitting diodes integrated onto the primary circuit board and positioned adjacent respective ones of the alphanumeric characters, and indicator control circuitry associated with the light emitting diodes which provides an indicator control signal in response to the sensor output signal, and wherein one of the light emitting diodes positioned adjacent a respective one of the alphanumeric characters corresponding to the selected transmission setting being illuminated or brightened in response to the indicator control signal.
In another form of the present invention, an inductive position sensor is provided which includes integrated light emitting diode (LED) indicators. In a further form of the present invention, an inductive position sensor is provided which is configured to sense the position of transmission gear selector lever, and to generate a sensor output signal that controls a visual indication system to provide a visually perceptible indication of the selected transmission setting. In one embodiment, the visual indication system includes LED indicators that are integrated onto the same circuit board that includes circuitry associated with the inductive position sensor. In a further form of the present invention, an inductive position sensor is provided which is configured to sense the position of transmission gear selector lever, and to generate a sensor output signal that controls actuation of the transmission. While the actual nature of the invention covered herein can only be determined with reference to the claims appended hereto, certain forms of the invention that are characteristic of the preferred embodiments disclosed herein are described briefly as follows.
It is one object of the present invention to provide an inductive position sensor with integrated LED indicators. Further objects, features, advantages, benefits, and aspects of the present invention will become apparent from the drawings and description contained herein.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is hereby intended, and that alterations and further modifications to the illustrated devices and/or further applications of the principles of the invention as illustrated herein are contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring to
In the illustrated embodiment of the invention, the gear shifter mechanism 10 is particularly suited for mounting at a central location on the floor of an automobile in an area above the transmission. However, in other embodiments, the gear shifter mechanism 10 may be mounted to the steering wheel column or at other locations within the vehicle. The console 12 includes an interior region which houses the components and devices associated with the gear shifter mechanism 10, the details of which are generally known to those skilled in the art and need not be discussed in herein. The console 12 includes an upper panel 30 including a slotted opening 32 through which extends the shaft of the gear selector lever 14. In one embodiment, the selector lever 14 is coupled to the transmission via a mechanical linkage and is configured for axial displacement within the slotted opening 32, back and forth along an axis of travel A, to correspondingly change the setting of the transmission. The selector lever 14 is movable successively through a predetermined sequence of positions, including a parking position, a reverse position, a neutral position, and one or more forward speed positions. Although one embodiment of the invention contemplates mechanical coupling of the gear selector lever 14 to the transmission, in other embodiments, a drive-by-wire or shift-by-wire system may be utilized which does not require a mechanical linkage or coupling between the gear selector lever 14 and the transmission. In such systems, the position of the gear selector lever 14 may be sensed via the positioning sensing system 18 or another type of position sensing system, which in turn generates an electrical output signal that may be used to control an actuator or drive that operates to shift the transmission to the particular setting corresponding to the position of the gear selector lever 14. As should be appreciated, elimination of the mechanical linkage or coupling between the gear selector lever and the transmission and replacing such mechanical systems with an electronic position sensing system tends to reduce mechanical complexity and manufacturing and assembly costs.
In the illustrated embodiment of the invention, the visual indication system 16 is includes an indicator panel located alongside the travel path of the selector lever 14 (i.e., generally parallel with the axis of travel A) and includes alphanumerical characters that serve to designate corresponding ones of the settings or modes of the transmission. In the illustrated embodiment, the indicator panel includes the alphanumerical characters of P, R, N, D, 3, L, which correspond to the transmission settings of park, reverse, neutral, drive, third gear, and low gear. However, it should be understood that the indicator panel may include other orders and sequences of alphanumerical characters corresponding to the settings of other types and configurations of transmissions. It should also be understood that the alphanumerical characters need not necessarily include both letters and numbers, and may include signs or symbols. The visual indication system 16 also includes a series of indicator lights or LED indicators 20 positioned adjacent respective ones of the alphanumerical characters. As will be discussed in greater detail below, the position sensing system 18 is configured to sense the position of the gear selector lever 14 associated with a select transmission setting, and generates an electronic signal that illuminates or brightens the LED adjacent the alphanumerical character corresponding to the selected transmission setting to provide the driver with a visually perceptible indication of the selected transmission setting.
Although the illustrated embodiment of the visual indication system 16 includes six LED indicators 20, it should be understood that the visual indication system 16 may include any number of LED indicators. Additionally, although the illustrated embodiment of the visual indication system 16 shows the LED indicators 20 positioned laterally adjacent the alphanumerical characters, in other embodiments, the indicator panel associated with the visual indication system 16 may be formed of a transparent or translucent material, with the alphanumerical characters also being transparent or translucent. In such embodiments, the LED indicators 20 may be positioned beneath the alphanumerical characters such that illumination or brightening of a particular LED indicator 20 will illuminate or brighten the corresponding alphanumerical character. Such backlighting arrangements are well known to those of skill in the art and need not be discussed in further detail herein. Additionally, it should be understood that the LED indicators 20 may be of the same color (i.e., white) or may be provided in different colors (i.e., white, red, blue, yellow, etc.). Bi-color and/or multi-color RGB-type LED indicators may also be used. Furthermore, the LED indicators 20 may be turned on and off to indicate the selected transmission setting, or the brightness of the LED indicator 20 associated with the selected transmission setting may be increased to produce a higher luminous output or illumination intensity relative to the other LED indicators 20 to provide a visually perceptible indication of the selected transmission setting.
Referring to
In the illustrated embodiment of the invention, the stationary pad 50 is mounted in a horizontal orientation, with the surfaces of the stationary pad 50 including the position sensor circuitry 52 facing vertically. However, other embodiments are also contemplated wherein the stationary pad 50 may be mounted in a vertical orientation, with the surfaces of the stationary pad 50 including the position sensor circuitry 52 facing horizontally. Additionally, in the illustrated embodiment, the movable puck 100 is positioned below and displaced along a downwardly facing surface of the stationary pad 50. However, in another embodiment, the movable puck 100 may be positioned above and displaced along an upwardly facing surface of the stationary pad 50. Furthermore, in the illustrated embodiment, the position sensor 18 is configured such that the movable puck 100 is displaced in horizontal directions along the arrows B and C relative to the stationary pad 50. However, other embodiments are also contemplated wherein the position sensor 18 may be configured such that the movable puck 100 is displaced in vertical directions along arrows B and C relative to the stationary pad 50. Other mounting arrangements and orientations of the stationary pad 50 and the movable puck 100 are also contemplated as falling within the scope of the present invention.
In the illustrated embodiment of the invention, the position sensor 18 is configured as a linear position sensor wherein movement of the puck 100 relative to the pad 50 comprises linear movement. However, other embodiments are also contemplated wherein the position sensor 18 may be configured as a rotary position sensor such that movement of puck 100 relative to the pad 50 comprises rotational movement. Additionally, although the travel path of the puck 100 has been illustrated and described as being substantially linear, other travel paths are also contemplated, including arced or curved travel paths, curvilinear travel paths, or any other non-linear travel path that would occur to one of skill in the art. In the illustrated embodiment of the invention, the position sensor 18 is configured to sense movement of the puck 100 and the gear selector lever 14 along a single axis arranged generally parallel to the axis of travel A. However, in other embodiments, the position sensor 18 may be configured to sense movement of the puck 100 and the gear selector lever 14 along multiple axes, such as, for example, a first axis arranged generally parallel to the axis of travel A and a second axis arranged generally perpendicular to the axis of travel A (i.e., an x-axis and a y-axis). Such a configuration would be particularly suitable for use in association with a manual transmission wherein movement of the gear selector lever 14 occurs in multiple directions (i.e., forward-backward and side-to-side).
In the illustrated embodiment of the invention, the stationary pad 50 including the position sensor circuitry 52 comprises a circuit board 54 onto which is printed conductive tracks or traces 56 which are laid out to define coils or windings having particular shapes and configurations. Additionally, the movable puck 100 including the position sensor circuitry 102 comprises a circuit board 104 onto which is printed conductive tracks or traces 106 that are laid out to define a rectangular-shaped resonant coil or winding 108. As shown schematically in FIGS. 5 and 6A-6C, the tracks or traces 56 associated with the circuit board 54 are laid out to define a sine or transmit coil 60 and a cosine or transmit coil 62 which comprise excitation windings, and a sense or receive coil 64 which comprises a sensor winding. As shown in
In the illustrated embodiment, the circuit board 54 associated with the stationary pad 50 has an L-shaped configuration, including a generally rectangular-shaped elongate section 70 and a base section 72. The circuit board 54 may be provided with a number of mounting features 74 for mounting the circuit board to a substrate, such as, for example, to the upper panel 30 of the gear shifter console 12. The elongate section 70 of the circuit board 54 is generally aligned along the axis of travel A (
The circuit board 54 including the position sensor circuitry 52 also includes a position sensor control unit 66 which is preferably integrated onto the base section 72 of the circuit board 54. In one embodiment, the position sensor control unit 66 is provided as an application specific integrated circuit (ASIC) integrated onto the circuit board 54. However, other types and configurations of position sensor control circuits are also contemplated as would be apparent to one of ordinary skill in the art. One of the primary functions of the position sensor control unit 66 is to generate transmit signals which are provided to the sine and cosine coils 60 and 62. In one exemplary embodiment of the invention, the transmit signal provided to the sine coil 60 is a 4 MHz radio frequency signal that is 100 percent amplitude modulated by a 4 kHz square wave, and the transmit signal provided to the cosine coil 62 is a 4 MHz modulated square wave signal that is phase delayed relative to the sine square wave by ninety electrical degrees. The resonant coil 108 which may comprise a 4 MHz resonant circuit is positioned over the sine, cosine, and sensor coils 60, 62 and 64 and which is displaced back and forth along the coils as the sensor element 100 is displaced relative to the base element 50 in the directions of arrows B and C.
The resonant coil 108 is electromagnetically coupled to the sine and cosine coils 60 and 62, and electromagnetic energy generated by the sine and cosine coils 60 and 62 is transmitted to and received by the resonant coil 108. The resonant coil or winding 108 receives electromagnetic energy from both the sine and cosine coils 60 and 62, which in turn generates a circulating resonant current within the resonant coil 108. The resonant coil 108 is also electromagnetically coupled to the sense coil 64, and electromagnetic energy generated by the circulating current within the resonant coil 108 is transmitted to and received by the sense coil 64. An electronic signal is generated within the sense coil 64 which corresponds to the physical position of the resonant coil 108 relative to the sine, cosine and sense coils 60, 62 and 64, which in turn corresponds to the physical position of the movable puck 100 relative to the stationary pad 50. Since the movable puck 100 is fixedly coupled to the gear selector lever 14, the electrical signal generated within the sense coil 64 corresponds to the particular position of the gear selector lever 14, which in turn corresponds to the selected transmission setting. The electronic signal generated within the sense coil 64 (which corresponds to the position of the movable puck 100 relative to the stationary pad 50) is transmitted to the position sensor control unit 66. As will be discussed below, the position sensor control unit 66 in turn generates an output signal which is transmitted to the control circuitry associated with the visual indication system 16 to correspondingly control illumination of the LED indicators 20.
Further details regarding the inductive position sensor 18 are illustrated and described in U.S. Pat. No. 7,208,945 to Jones et al., the contents of which are incorporated herein by reference in their entirety. Specific details regarding the components associated with the inductive position sensor 18 and operation thereof are illustrated and described in the '945 patent, and therefore need not be specifically discussed herein. Although a particular configuration of the inductive position sensor 18 is illustrated and described herein, it should be understood that other types and configurations of inductive position sensors are also contemplated for use in association with the present invention.
As shown in
In one embodiment of the invention, the LED indicators 20 and the resistive elements 82 associated with the LED indictor control circuitry 80 are integrated onto the elongate section 70 of the circuit board 54 and are positioned adjacent the sine, cosine and sense coils 60, 62, 64 of the inductive position sensor 18. The diode elements 84 and the LED control unit 88 are preferably integrated onto the base section 72 of the circuit board 54 adjacent the position sensor control unit 66 at a location remote from the position sensor coils 60, 62, 64. In the illustrated embodiment, the LED indicators 20 and the resistive elements 82 are located outside of the inner region of the sense coil 64 which surrounds the sine and cosine coils 60, 62. However, as will be illustrated and described below, the LED indicators 20 may be positioned within the inner region of the sense coil 64. In still other embodiments, the resistive elements 82 may also be positioned within the inner region of the sense coil 64. Although the LED indicators 20 and the resistive elements 82 are illustrated and described as being integrated onto the elongate section 70 of the circuit board 54 adjacent the position sensor coils 60, 62, 64, it should be understood that in other embodiments, the LED indicators 20 and/or the resistive elements 82 may be positioned at other locations on the circuit board 54. Additionally, although the diode elements 84 and the LED control unit 88 are illustrated and described as being integrated onto the base section 72 of the circuit board 54, in other embodiments, the diode elements 84 and/or the LED control unit 88 may be positioned at other locations on the circuit board 54.
As should be appreciated, combining the LED indicators 20 and the LED indicator control circuitry 80 onto a common circuit board 54 which includes the position sensor circuitry 52 tends to decrease manufacturing and assembly costs. Additionally, it has been found that integration of the LED indicators 20 and the LED control circuitry 80 onto the circuit board 54 which includes the position sensor circuitry 52 does not degrade the functionality or accuracy of the inductive position sensor 18. More particularly, it has been found that positioning of the LED indicators 20 and the resistive elements 82 associated with the LED control circuitry 80 in close proximity with the inductive position sensor circuitry 52 (i.e., the sine, cosine and sensor coils 60, 62, 64) does not lead to disruption or unbalancing of the operating conditions associated with the inductive position sensor 18. Additionally, integration of the LED indicators 20 and the LED control circuitry 80 onto the common circuit board 54 does not generate noise or other undesirable signals within the inductive position sensor circuitry 52. Accordingly, the present invention provides the gear shifter mechanism 10 with the capability of sensing the position of the gear selector lever 14 and to provide a visual indication of the sensed position of the gear selector lever 14 which corresponds to the selected transmission setting. It should be appreciated that the position sensing and visual indication capabilities are provided in a cost effective manner while maintaining acceptable levels of accuracy and reliability.
Referring to
Referring to
In the illustrated embodiment of the invention, the position sensor control unit 66 is provided with power/ground terminals and a signal output S1 that is electrically connected to an input of the LED control unit 88. In one embodiment, the output signal generated by position sensor control unit 66 falls within a range of about 0.2 V to 4.8 V, with the output signal voltage corresponding to a particular position of the sensor puck 100 relative to the sensor pad 50, and more specifically the position of the sensor circuitry 102 relative to the sensor circuitry 52. However, it should be understood that the output signal generated by position sensor control unit 66 may fall within other voltage ranges. As indicated above, the position of the sensor puck 100 corresponds to the position of the gear shifter lever 14. Accordingly, the output signal generated by the position sensor control unit 66 corresponds to a particular position of the gear shift selector lever 14, which in turn corresponds to a selected transmission setting.
The LED control unit 88 is provided with power/ground terminals and a signal output S2 which may be connected to a controller or computing device associated with another electronic system associated with the vehicle. In one embodiment, the signal output S2 may be connected to a system configured to calibrate and/or test the visual indication system 16 and/or the position sensing system 18. In another embodiment, the signal output S2 may be connected to another visual indication system, such as a dashboard indication system, to provide an input signal to control the operation of other lights or indicators. In other embodiments, the signal output S2 may be connected to an engine or transmission control system or computer to provide an input signal corresponding to the selected transmission setting. The LED control unit 88 may also be provided with other inputs and outputs as would occur to one of ordinary skill in the art. The resistive elements 82 and the diode elements 84 are integrated into the LED control circuitry 80 per the schematic of
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
The present application claims the benefit of U.S. Provisional Application No. 60/997,720 filed on Oct. 4, 2007, the contents of which are hereby incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60997720 | Oct 2007 | US |
