Inertial measurement unit

About: Inertial measurement unit is a research topic. Over the lifetime, 13326 publications have been published within this topic receiving 189083 citations. The topic is also known as: IMU.

Data Fusion of UWB and IMU Based on Unscented Kalman Filter for Indoor Localization of Quadrotor UAV

Abstract: The indoor location technique plays a essential role during the application of quadrotor unmanned aerial vehicle (UAV). However, the control design problem for the quadrotor UAV is quite difficult in the indoor environment due to the weak GPS signal. Based on Ultra Wide Band (UWB), the related positioning issues can be solved of UAV through base station with known coordinate position and equipment with location tag, but it is difficult to meet the high-precision operation requirements. In this paper, an indoor positioning design method combined with the Inertial Measurement Unit (IMU) and UWB positioning technology is proposed, which can effectively suppress the error accumulation of the IMU and further improve the positioning accuracy. Moreover, the system architecture for a class of quadrotor UAV is designed. The multisensor fusion technology based on unscented Kalman filter (UKF) is used to avoid neglecting the high-order terms of the nonlinear observation equations of UWB and IMU, which can effectively improve the accuracy of solving the nonlinear equations. Finally, a hardware-in-the-loop simulation platform is designed to verify the effectiveness of the indoor positioning method and improve the positioning accuracy.

Arrangement for and method of two dimensional and three dimensional precision location and orientation determination

Abstract: In one embodiment of the present invention, a method of and apparatus for determining inaccurate GPS samples in a set of GPS samples is disclosed, according to the following actions: a) obtaining GPS samples as taken by a global positioning system on board a vehicle when traveling along a trajectory; b) obtaining a first estimation of the trajectory based on the GPS samples; c) obtaining a second estimation of the trajectory at least based on measurements made by an inertial measurement unit on board vehicle when traveling along the trajectory; d) comparing the first and second estimations; e) establishing locations where the first estimation shows a variation compared with the second estimation above a predetermined threshold; f) if no such locations can be established continue with action j), otherwise continue with action g); g) removing GPS samples associated with the locations of high variation as being inaccurate GPS samples, thus forming a set of remaining GPS samples; h) calculating the first estimation anew of the trajectory based on the remaining GPS samples and calculating the second estimation anew; i) repeating actions d) to h); j) ending the actions.

A new wearable input device: SCURRY

Abstract: A new wearable input device named SCURRY, developed by the Samsung Advanced Institute of Technology, is introduced in this paper. Based on inertial sensors, this device allows a human operator to select a specified character, an event, or an operation as the input he/she wants spatially through both hand motion and finger clicking. It is a glovelike device, which can be worn on the human hand, composed of a base module, including one controller and two angular-velocity sensors (gyroscopes) on the back of the hand, and four ring-type modules (rings), including two-axis acceleration sensors (accelerometers) on four fingers. The base and the ring modules are integrated modules containing sensors, a transceiver or receiver for communication, and a microcontroller, which makes the device compact and light. The two gyroscopes embedded in the base module have a role in detecting the direction (up, down, right, and left) of the hand motion, and the accelerometers have a role in detecting finger motion generated by finger clicking. An algorithm for the exact finger-click recognition composed of three parts (feature extraction, valid-click discrimination, and crosstalk avoidance) is proposed to improve the recognition performance of finger clicking on SCURRY. The experimental results and discussions are presented. SCURRY can be used as a wearable mouse spatially, by allowing any three fingers to be operated as the left, middle, and right mouse buttons, and in a similar manner, as a wearable keyboard, as it allows a human operator to point and select any character, event, or operation by his hand motion and finger clicking.

A preliminary test of measurement of joint angles and stride length with wireless inertial sensors for wearable gait evaluation system

Abstract: The purpose of this study is to develop wearable sensor system for gait evaluation using gyroscopes and accelerometers for application to rehabilitation, healthcare and so on. In this paper, simultaneous measurement of joint angles of lower limbs and stride length was tested with a prototype of wearable sensor system. The system measured the joint angles using the Kalman filter. Signals from the sensor attached on the foot were used in the stride length estimation detecting foot movement automatically. Joint angles of the lower limbs were measured with stable and reasonable accuracy compared to those values measured with optical motion measurement system with healthy subjects. It was expected that the stride length measurement with the wearable sensor system would be practical by realizing more stable measurement accuracy. Sensor attachment position was suggested not to affect significantly measurement of slow and normal speed movements in a test with the rigid body model. Joint angle patterns measured in 10m walking with a healthy subject were similar to common patterns. High correlation between joint angles at some characteristic points and stride velocity were also found adequately. These results suggested that the wireless wearable inertial sensor system could detect characteristics of gait.