Angle measurement system

#For precise control of electrically commutated engines and electrical drives, fast and accurate measurement of the angular position of the rotating motor or drive shaft is required. One conventional approach for measuring such an angular position is to use incremental angular position sensors, such as a tooth wheel or pole wheel type sensors, for example. While incremental sensors typically provide accurate measurement, even at high speeds, they provide only discrete (not continuous) angle measurements. Another approach is to use magnetoresistive type angle sensors, such as giant magnetoresistive (GMR) and anisotropic magnetoresistive (AMR) angle sensors, to measure the angular position. While such angle sensors provide continuous angle measurement, they typically do not provide the required accuracy, particularly at high rotational speeds. As a result, commonly employed techniques often involve using optical encoders or synchro-resolvers which, although providing accurate angle measurement, are complicated and costly.

#For these and other reasons, there is a need for the embodiments of the present disclosure.

#One embodiment provides an angular position measurement system including a continuous angular position sensor configured to provide a first signal representative of a continuous angular position of a rotating shaft, an incremental angular position sensor configured to provide a second signal representative of incremental angular positions of the rotating shaft, and a controller configured to calibrate the first signal based on the second signal to provide a third signal representative of a calibrated continuous angular position of the rotating shaft.

#The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification. The drawings illustrate the embodiments of the present invention and together with the description serve to explain the principles of the invention. Other embodiments of the present invention and many of the intended advantages of the present invention will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

#FIG. 1 is a side view generally illustrating an angle measurement system according to one embodiment.

#FIG. 2 is a cross-sectional view illustrating portions of a wheelspeed sensor suitable for use with the angle measurement system of FIG. 1 according to one embodiment.

#In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

#The present disclosure describes embodiments of an angle measurement system for measuring an angular position of a rotating shaft which employs a magnetoresistive angle sensor (e.g. GMR, AMR), or other suitable type of continuous angle measurement device, which provides an output representative of a continuous angular position of the rotating shaft and which is calibrated based on an output of an incremental position sensor, such as a tooth wheel or pole wheel type position sensor, for example

#FIG. 1 generally illustrates one embodiment of an angle measurement system 30 according to the present disclosure for measuring the angular position of a rotating member, such as rotating shaft 50. Shaft 50 may be any number of rotating members, such as a motor shaft or a shaft of an electrical drive, for example. Angle measurement system 30 includes an incremental angular position speed sensor 32, a continuous angular position sensor 34, and a controller 36. According to one embodiment, incremental angular position sensor 32 is a wheelspeed sensor. Wheelspeed sensor 32 provides an incremental angular position signal 33 (e.g. an analog signal) representative of incremental angular positions of rotating shaft 50, and continuous angular position sensor 34 provides a continuous angular position signal 35 representative of a continuous angular position of shaft 50. Controller 36, as will be described in greater detail, provides a corrected or calibrated continuous angular position signal 37 representative of the continuous angular position of rotating shaft 50 based on incremental position signal 33 and on continuous angular position signal 35.