state derivation of a 12-axis gyroscope-free inertial measurement unit的状态推导12-axis gyroscope-free惯性测量单元.pdf

Sensors 2011, 11, 3145-3162; doi:10.3390/s110303145 OPEN ACCESS sensors ISSN 1424-8220 /journal/sensors Article State Derivation of a 12-Axis Gyroscope-Free Inertial Measurement Unit Jau-Ching Lu and Pei-Chun Lin * Department of Mechanical Engineering, National Taiwan University, No.1 Roosevelt Rd. Sec.4, ME Eng. Bldg. Room 503-3, Taipei, Taiwan; E-Mail: .tw * Author to whom correspondence should be addressed; E-Mail: peichunlin@.tw; Tel.: +886-2-3366-9747; Fax: +886-2-2363-1755. Received: 28 December 2010; in revisedform: 6 February 2011 / Accepted: 22 February 2011 / Published: 14 March 2011 Abstract: The derivation of linear acceleration, angular acceleration, and angular velocity states from a 12-axis gyroscope-free inertial measurement unit that utilizes four 3-axis accelerometer measurements at four distinct locations is reported. Particularly, a new algorithm which derives the angular velocity from its quadratic form and derivative form based on the context-based interacting multiple model is demonstrated. The performance of the system was evaluated under arbitrary 3-dimensional motion. Keywords: inertial measurement unit; accelerometer; gyroscope-free; angular velocity; interacting multiple model; context-based 1. Introduction Inertial sensors have been widely used in various applications, including motion detection [1], body state estimation [2-4], navigation [5-7], microsurgery [8], rehabilitation [9], etc. Traditionally a standard inertial measurement unit (IMU) compris