Embodiments are generally related to sensor methods and systems. Embodiments are also related to position detection devices. Embodiments are additionally related to magnetic sensors. Embodiments also relate to methods and systems for linear and rotary sensing applications. Embodiments additionally relate to thermal compensation methods and systems.
Magnetoresistive (MR) array technology is utilized in a variety of commercial, consumer and industrial detection applications. In some conventional MR systems an apparatus can be provided for determining the position of a member movable along a path. In such a device, a magnet can be attached to the movable member and an array of magnetic field transducers are located adjacent the path. As the magnet approaches, passes and moves away from a transducer, the transducer provides a varying output signal, which can be represented by a single characteristic curve that is representative of any of the transducers.
To determine the position of the movable member, the transducers are electronically scanned and data is selected from a group of transducers having an output that indicates relative proximity to the magnet. A curve-fitting algorithm can then be utilized to determine a best fit of the data to the characteristic curve. By placement of the characteristic curve along a position axis, the position of the magnet and therefore the movable member may be determined.
In another conventional MR device, a position determining apparatus can be implemented, which includes a magnet that is attached to a movable member that moves along a predefined path of finite length. An array of magnetic field transducers can be located adjacent to the predefined path. The transducers can provide an output signal as the magnet approaches passes and moves away from each transducer. A correction mechanism can also be provided to correct for residual error caused by the non-linearity of the transducers.
Such a correction mechanism preferably approximates the residual error with a predetermined function, and applies correction factors that correspond to the predetermined function to offset the residual error. By correcting for the non-linearity of the transducers, the length of the magnet may be reduced and/or the spacing of the transducers may be reduced.
An example of a conventional magnetic sensing approach is disclosed, for example, in U.S. Pat. No. 5,589,769, “Position Detection Apparatus Including a Circuit for Receiving a Plurality of Output Signal Values and Fitting the Output Signal Values to a Curve,” which issued to Donald R. Krahn on Dec. 31, 1996, and is assigned to Honeywell International Inc. Another example of a magnetic sensing approach is disclosed in U.S. Pat. No. 6,097,183, “Position Detection Apparatus with Correction for Non-Linear Sensor Regions,” which issued to Goetz et al. on Aug. 1, 2000 and is also assigned to Honeywell International Inc. U.S. Pat. Nos. 5,589,769 and 6,097,183 are incorporated herein by reference in their entirety. Such MR-based devices generally utilize discrete components on a Printed Circuit Board (PCB) assembly to yield the resulting function.
One of the problems with magnetoresistive sensors, particularly anisotropic magnetoresistive (AMR) sensors based on an array configuration, is that such systems typically rely upon the use of an array of magnetoresistive elements configured with equal spacings. In the case of linear arrays, this means that the linear centerline-to-centerline spacings are nominally equal. While appropriate for some configurations, this regular spacing prevents high accuracy sensing. One approach for improving sensing involves introducing additional magnetoresistive elements. This approach, however, only adds to the overall production costs of the sensor device. It is therefore believed that a solution to the problems associated with such prior art sensor devices is the design and configuration of an array based on regular spacing, but on irregular spacing, as discussed in greater detail herein.
The following summary is provided to facilitate an understanding of some of the innovative features unique to the embodiments and is not intended to be a full description. A full appreciation of the various aspects of the embodiments disclosed can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
It is, therefore, one aspect of the present invention to provide for improved sensor methods and systems.
It is another aspect of the present invention to provide for an improved position detection device
It is a further aspect of the present invention to provide for an improved AMR sensor.
It is an additional aspect of the present invention to provide for improved linear and rotary sensing applications.
It is yet another aspect of the present invention to provide a magnetoresistive sensor array system wherein magnetoresistive sensing components thereof are spaced from one another in an irregular manner in order to optimize sensor data results thereof.
The aforementioned aspects of the invention and other objectives and advantages can now be achieved as described herein. A magnetoresistive sensor system is disclosed, which includes a plurality of chip carriers, such that each integrated circuit among the plurality of chip carriers is associated with a respective magnetoresistive sensing components. A plurality of magnetoresistive sensing components can be arranged in an array, wherein each magnetoresistive component among the plurality of magnetoresistive components is associated with a respective integrated circuit among the plurality of chip carriers and wherein the plurality of magnetoresistive sensing components comprises sensing components that are spaced irregular from one another in order to optimize the performance of the array and meet requirements of a particular magnetoresistive sensing application.
This can be configured as a linear array or a rotary array, depending upon design considerations. The array can also be configured on a printed circuit board (PCB). In general, by decreasing the spacing between two elements in a particular region of interest, increased accuracy can be achieved over this region. Varying element spacings can be designed into the array to offer varying performance levels by region.
The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the embodiments and, together with the detailed description, serve to explain the principles of the disclosed embodiments.
The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope of the invention.
Chip carrier 160 includes a plurality of electrical connections or pins 110, 112, 114, 116, 118, 120, 122, 124. Similarly, chip carrier 162 includes a plurality of electrical connections or pins 126, 128, 130, 132, 134, 136, 138, 140. Likewise, chip carrier 164 includes a plurality of electrical connections or pins 142, 144, 146, 148, 150, 152, 154, 156. In general the chip carriers 160, 162, 164 and respective AMR bridge circuits 121, 123, 125 can be grouped together to form a magnetoresistive array or system 100. Note that although only three AMR bridge circuits 121, 123, 125 are depicted in
The movement of the biasing magnet 102 generates a sinusoidal signal response from each magnetoresistive bridge circuit 121, 123, 125. The AMR bridge outputs generated by magnetoresistive bridge circuits 121, 123, 125 are nearly identical to one another; however, their respective phases are shifted due to centerline-to-centerline spacing thereof. Varying sensing schemes can therefore be implemented to interpolate between the AMR bridge circuits 121, 123, 125 in order to achieve a high absolute accuracy.
It is important to appreciate that all previous magnetoresistive array and sensing configurations utilize an array of elements configured with equal spacing. In the case of linear arrays, this means that the linear centerline-to-centerline distance is nominally equal. In the case of rotary arrays, this means that the centerline-to-centerline arc is nominally equal.
Through simulation and analysis, it has been determined that a unique ability exists for optimizing the absolute accuracy in a particular region of an array by decreasing the spacing between the pair of elements in a region of interest. The spacing between the remaining elements within the array can then be increased to preserve the overall length of the array. Example simulated data is therefore described herein, which illustrates the significant performance increase that can be gained utilizing this approach.
The total length from the centerline of AMR bridge circuit 121 to the centerline of AMR bridge circuit 135 is represented by the variable “r”. Thus, in some implementations, the length “s” can be, for example, 12.00 mm, while the length “t” may be 10.00 mm. In such an implementation, the length “u” may be 8.00 mm, while the length or spacing “v” can be 6.00 mm. The length or spacing associated with the length “r” can be, for example, 66.00 mm. Thus, the eight element magnetoresistive array sensor system 1500 can be implemented, for example, as an eight element, 66.00 mm linear array with irregular spacing.
From the foregoing, it can be postulated that the Absolute Position Accuracy is a function of the amount of quantization levels (least significant bits or LSB's) per pair of elements and the spacing between those elements. The amount of quantization levels is determined by the electronic design and is fixed. However, the element spacing is a function of the magnetic circuit design and is easily optimized per application. Absolute accuracy is improved if the element spacing are moved closer together, but may be worsened if the element spacings are moved further apart.
If a high level of accuracy is desired across the whole length of the array, then a sufficient amount of elements must be utilized. However, if there is one particular region of interest within the array where a very high level of accuracy is desired but the accuracy does not have to be as high for the rest of the array, fewer elements may be utilized in the design. Only the particular area of interest where the high level of accuracy is desired needs to have small element spacing.
The previous figures generally rely upon linear magnetoresistive array configurations, which provide examples that explain the novelty of implementing irregular element spacings. This concept also applies to all rotary magnetoresistive array configurations as well, some examples of which are provided in greater detail as follows.
The process depicted in
The process depicted in
It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
This patent application is a continuation of U.S. patent application Ser. No. 11/227,411, entitled “Position Detection Utilizing an Array of Magnetic Sensors With Irregular Spacing Between Sensing Elements,” which was filed on Sep. 14, 2005, now U.S. Pat. No. 7,408,343, which is incorporated herein by reference, and is a continuation-in-part of U.S. patent application Ser. No. 10/993,964 filed Nov. 18, 2004, now U.S. Pat. No. 7,173,414, and is a continuation-in-part of U.S. patent application Ser. No. 11/088,104 filed Mar. 23, 2005, now U.S. Pat. No. 7,112,962.
Number | Name | Date | Kind |
---|---|---|---|
5351003 | Bauer et al. | Sep 1994 | A |
5358088 | Barnes et al. | Oct 1994 | A |
5430374 | Metz | Jul 1995 | A |
5497084 | Bicking | Mar 1996 | A |
5589769 | Krahn | Dec 1996 | A |
5750270 | Tang et al. | May 1998 | A |
6097183 | Goetz et al. | Aug 2000 | A |
6445176 | Wallrafen | Sep 2002 | B1 |
6509732 | Rhodes et al. | Jan 2003 | B1 |
6638691 | Kang et al. | Oct 2003 | B2 |
6674280 | Goetz et al. | Jan 2004 | B1 |
6731108 | Zalunardo et al. | May 2004 | B2 |
6750644 | Berkcan | Jun 2004 | B1 |
6757635 | Topmiller | Jun 2004 | B2 |
6806702 | Lamb et al. | Oct 2004 | B2 |
6972559 | Bartingale et al. | Dec 2005 | B2 |
6984978 | Wan et al. | Jan 2006 | B2 |
7030604 | Dmytriw et al. | Apr 2006 | B1 |
7126327 | Busch | Oct 2006 | B1 |
7141967 | Butzmann | Nov 2006 | B2 |
7173413 | Kurumado | Feb 2007 | B2 |
7173414 | Ricks et al. | Feb 2007 | B2 |
7208940 | Withanawasam et al. | Apr 2007 | B2 |
7408343 | Dmytriw et al. | Aug 2008 | B2 |
7449882 | Witcraft et al. | Nov 2008 | B2 |
20020167310 | Wallner et al. | Nov 2002 | A1 |
20030076090 | Muth | Apr 2003 | A1 |
20030158681 | Walter et al. | Aug 2003 | A1 |
20040070390 | Lamb et al. | Apr 2004 | A1 |
20040207392 | Kernhof | Oct 2004 | A1 |
20070001668 | Mock et al. | Jan 2007 | A1 |
Number | Date | Country |
---|---|---|
9953266 | Oct 1999 | WO |
0177622 | Oct 2001 | WO |
02065148 | Aug 2002 | WO |
Number | Date | Country | |
---|---|---|---|
20080284416 A1 | Nov 2008 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 11227411 | Sep 2005 | US |
Child | 12126752 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 11088104 | Mar 2005 | US |
Child | 11227411 | US | |
Parent | 10993964 | Nov 2004 | US |
Child | 11088104 | US |