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The paper presents the idea, design and performance evaluation of a low-cost Attitude and Heading Reference System (AHRS). It is based on an Inertial Measurement Unit (IMU), being a single sensor pack that provides all the raw data required to feed the designed filter. An extension of a complementary filter in form of feedback control system with PI controller, called 3D complementary filter provides...
In the paper, solution of the problem of vibrations which appears during the maneuvers of quadrocopters is presented. Those special kinds of vibration aren't related to mounting or manufacturing faults. In this kinds of flying machines the main sources of vibration comes from motors and/or propellers unbalance. The paper shows analytical description of the source of this problem. Mathematical description...
In this paper we study the existing CRT-RSA countermeasures against fault-injection attacks. In an attempt to classify them we get to achieve deep understanding of how they work. We show that the many countermeasures that we study (and their variations) actually share a number of common features, but optimize them in different ways. We also show that there is no conceptual distinction between test-based...
In order to drive the electric machines using the motors efficiently, the energy loss should be minimized during its operation. The optimal torque and rotating speed trajectories to minimize the energy loss of the induction motor (IM) during its operation has been proposed when the operation time, rotating speed, and rotational angle are given as drive conditions. However, the optimal trajectories...
Work deals with biped mechanical systems, so called exoskeletons. General purpose of this work is to construct control for exoskeleton motion similar to human walking. In the work the following problems are considered: kinematics synthesis based on motion capture technology, solving direct dynamics problems for finding control torques, full control system elaborating and verifying constructed system...
A pixel-wise method for absolute and local aortic pressures estimation using 3D velocities in MRI and carotid pressure curves to set-up reference pressure values is presented. This method is based on the Navier-Stokes equation and a fast iterative algorithm. Its reliability was demonstrated: 1) in a synthetic phantom by comparison against simplified Bernoulli equation applied at peak velocities, and...
The Domain Green's Function Method (DGFM) is a Method-of-Moments (MoM) based domain decomposition approach that is useful for the analysis of large, irregular antenna arrays. Mutual coupling between array elements is accounted for with the formulation of an active impedance matrix equation for each of the domains/array elements. The active current distribution on the entire array geometry is then...
Legged systems are potentially expected to have outstanding mobility. However, they have shown only modest levels of capability to traverse on flat ground. This paper introduces a biped robot inspired by the hind limbs of cats. We present the characteristics of the system and conduct a position analysis based on vector loop equations. Afterwards, the ground clearance and parallel movement of the robotic...
In autonomous quadrocopter navigation, wind disturbances commonly pose a problem for the vehicle to navigate precisely on the planned path. The vehicle easily deviates off from the path and obviously affects the navigation accuracy. Trajectory correction is one possible solution proposed by few researchers to avert the problem. The approaches are proven to increase the efficiency for the vehicle to...
Contact scanning scanners system can check deterioration of structure and inside matter during the production process. However, in case of high-speed scanning, oscillation occurs in the sensor part due to unevenness and friction on the measured surface. To overcome the problem, we have proposed an oscillation control scheme for scanning scanners system. In this paper, to show usefulness of the proposed...
Since Underwater Vehicle-Manipulator Systems (UVMS) are expected to make important roles in ocean exploration, many studies about control of single arm UVMSs have been reported. We have also been proposed digital Resolved Acceleration Control (RAC) methods for a single arm UVMS. In this paper, we propose a discrete time RAC method for multiple arms UVMS. Simulation results show the effectiveness of...
The focus of this paper is to develop a control system for wearable motion assist device giving physical support for people who are doing physically demanding tasks. Two key technical issues in developing such a device are how to generate the reference trajectory for the actuator installed to provide appropriate motion support, and how to determine the strength and duration of assist to help complete...
The calculation of Fock-Exchange integral is becoming an important computational challenge in solving the quantum properties of systems with many electrons. In this work we show how techniques that are used in electromagnetic simulations for the similar Poisson equation can help in accelerating the calculation of such exchange integrals. The approach we present can be especially efficient for quasi-planar...
Along with the coming of the aging society, the passive robot walking helper is introduced for providing safe mobility for the elderly, which features continuous energy dissipation from the system with brakes for steering. When this passive walking helper is applied for guidance and obstacle avoidance, it is crucial to determine proper braking torques in accordance with user-applied force for avoiding...
Monitoring lower body motion, especially gait pattern, using low cost Inertial Measurement Units on a daily basis is becoming critically important for the diagnosis and rehabilitation of neurological diseases. The current state of the art algorithm is to double integrate motion acceleration and compensate cumulative errors by resetting velocity signals to zero at the stance-phase of each stride. However,...
We propose a new heel-contact toe-off walking model based on the Linear Inverted Pendulum (LIP) model, which due to the linearity and the ease of manipulation of the equations, could be considered to be advantageous for a future online implementation for the generation of walking patterns. This new model is based on the so called functional rockers of the foot (heel, ankle and forefoot rockers), each...
In the present study we analyze the speed, acceleration, torque, boiler power during a complete phase of human walking and of the change of state: from sitting position to standing position. As a part of the experimentation methodology, we use artificial vision and with this we capture the points located in: hip, knee and ankle, these are states join by segments, to finally obtain the variation of...
In this paper, the Small Unmanned Aerial Vehicles (SUAVs)' navigation, attitude and velocity control are integrated into a simple, unified Hierarchy-Structured Incremental Dynamic Inversion (HSIDI) control system. Firstly, based on singular perturbation theory, all the variables of the SUAVs' dynamics are divided into four groups according to time-scale, and four Dynamic Inversion (DI) subsystems...
The relative equations between interceptor and target are conducted in rotation coordinate of Line of Sight. An error propagate model of LOS rate is established which is based on CADET (Covariance Analysis Describing Function Technique). This model takes several factors into consideration, such as estimate error of LOS rate, acceleration saturation of interceptor, sampling rate. A set of analytical...
In the traditional terminal guidance, the state estimator and guidance law are design independently by assuming the validity of the separation principle and the certainty equivalence principle, which are only valid for linear systems with Gaussian noise. This paper considers the nonlinear terminal guidance system for a target interception problem by multiple vehicles. Firstly, the probability density...
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