The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 19, 2017
Filed:
Oct. 02, 2015
Sharp Laboratories of America (Sla), Inc., Camas, WA (US);
Bryan Hallberg, Vancouver, WA (US);
Sharp Laboratories of America, Inc., Camas, WA (US);
Abstract
A system and method are provided for determining the orientation of an inertial measurement unit (IMU). The method calculates a gyroscopic quaternion, and when the IMU accelerometer reading is about equal to gravity (1 G), a field quaternion is calculated using IMU accelerometer readings. Estimates are made of angular orientation errors due to IMU angular velocity and linear acceleration, and these angular orientation errors are used to selectively mix the gyroscopic quaternion and field quaternion to supply a current sample quaternion. Alternatively, if the accelerometer reading is not about equal to 1 G, the gyroscopic quaternion is used as the current sample quaternion. In one aspect, IMU gyroscope readings and IMU accelerometer readings are calibrated in response to determining a lack of IMU movement. Near-zero gyroscope reading jitter is removed by setting the IMU gyroscopic reading to zero, when the gyroscopic reading is near zero.