In this paper we describe a controller and sensor fusion algorithm for a low-cost commercial quadrotor helicopter and its implementation in ROS. The dynamics of the system is assumed decoupled and identified as four S...
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In this paper we describe a controller and sensor fusion algorithm for a low-cost commercial quadrotor helicopter and its implementation in ROS. The dynamics of the system is assumed decoupled and identified as four SISO systems using subspace state-space system identification methods. A simple PD controller is designed using these open loop transfer functions and evaluated in simulation.
In this paper techniques are introduced for orientation estimation of wearable devices (like Google Glass) through bias compensation of gyroscope. The standard problem of using gyroscopes is that integration of raw an...
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ISBN:
(纸本)9781479972807
In this paper techniques are introduced for orientation estimation of wearable devices (like Google Glass) through bias compensation of gyroscope. The standard problem of using gyroscopes is that integration of raw angular rates with non-zero bias will lead to continuous drift of the estimated orientation. To examine the nature of this bias, a simple error model was constructed for the whole device in terms of inertial sensing. For eliminating the bias, a sensor fusion algorithm was developed using the benefits of optical flow from the camera of the device. Our orientation estimator and bias removal method is based on complementary filters, in combination with an adaptive reliability filter for the optical flow features. The feedback of the fused result is combined with the raw gyroscope angular rates to compensate the bias. Various measurements were recorded on a real device running the demanding optical flow onboard. This way a robust and reliable fusion was constructed, which matched our expectations, and has been validated with simulations and real world measurements.
The design of attitude determination and control of nanosatellites requires innovative solutions that are low-cost, small in size, and minimized power consumption. The University of Manitoba T-Sat1 project has created...
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ISBN:
(纸本)9781479900336;9781479900312
The design of attitude determination and control of nanosatellites requires innovative solutions that are low-cost, small in size, and minimized power consumption. The University of Manitoba T-Sat1 project has created a simple complement of sensors and actuators that can provide stable determination and orientation. The linear region of photodiode readings was combined with magnetometer readings in a sensor-fusion attitude determination algorithm. The actuators were custom-built torque discs on printed circuit boards that proved easy to mount and generate fields 25 nT that are sufficient to orient the satellite while in orbit. The torque disc manufacturing process is described with details on the imperfections and lessons learned from the prototypes. This paper describes the hardware and software design and implementation for the attitude determination and control of the T-Sat1 nanosatellite.
The design of attitude determination and control of nanosatellites requires innovative solutions that are low-cost, small in size, and minimized power consumption. The University of Manitoba T-Satl project has created...
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ISBN:
(纸本)9781479900312
The design of attitude determination and control of nanosatellites requires innovative solutions that are low-cost, small in size, and minimized power consumption. The University of Manitoba T-Satl project has created a simple complement of sensors and actuators that can provide stable determination and orientation. The linear region of photodiode readings was combined with magnetometer readings in a sensor-fusion attitude determination algorithm. The actuators were custom-built torque discs on printed circuit boards that proved easy to mount and generate fields 25 nT that are sufficient to orient the satellite while in orbit. The torque disc manufacturing process is described with details on the imperfections and lessons learned from the prototypes. This paper describes the hardware and software design and implementation for the attitude determination and control of the T-Satl nanosatellite.
Smartphones are largely benefiting from the ever increasing rate of integration of mobile IT components. Their increasing processing power and the fact that they are fitted with GNSS-receivers make them ideal for hand...
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ISBN:
(纸本)9781424458646
Smartphones are largely benefiting from the ever increasing rate of integration of mobile IT components. Their increasing processing power and the fact that they are fitted with GNSS-receivers make them ideal for hand-held pedestrian navigation solutions. This document proposes a pedestrian indoor navigation system based on a custom inertial navigation system and the N900 smartphone made by Nokia. The system does not depend on a particular indoor navigation system, but attempts to support its inertial navigation system by selecting the optimal set of auxiliary information from available infrastructure such as WLAN and bluetooth. Analysis focuses on the development of the inertial navigation hardware, the definition of an optimal set of support information and the development of an efficient sensor fusion algorithm.
作者：
Kumar, NSJann, TNatl Aerosp Labs
Flight Mech & Control Div Bangalore 560017 Karnataka India DLR
Inst Flugsystemtech Braunschweig Germany
Due to costs, size and mass, commercially available inertial navigation systems are not suitable for small, autonomous flying vehicles like ALEX and other UAVs. In contrast, by using modern MEMS (or of similar class) ...
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Due to costs, size and mass, commercially available inertial navigation systems are not suitable for small, autonomous flying vehicles like ALEX and other UAVs. In contrast, by using modern MEMS (or of similar class) sensors, hardware costs, size and mass can be reduced substantially. However, low-cost sensors often suffer from inaccuracy and are influenced greatly by temperature variation. In this work, such inaccuracies and dependence on temperature variations have been studied, modelled and compensated in order to reach an adequate quality of measurements for the estimation of attitudes. This has been done applying a Kalman Filter-based sensor fusion algorithm that combines sensor models, error parameters and estimation scheme. Attitude estimation from low-cost sensors is first realized in a Matlab/Simulink platform and then implemented on hardware by programming the micro controller and validated. The accuracies of the estimated roll and pitch attitudes are well within the stipulated accuracy level of +/-L5degrees for the ALEX. However, the estimation of heading, which is. mainly derived from the magnetometer readings, seems to be influenced greatly by the variation in local magnetic field.
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