The main contribution of this paper is the development of a novel attitude observer based on a triaxial high-grade rate gyro and single body-fixed vector measurements of a constant inertial vector, in contrast with ty...
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ISBN:
(纸本)9781467360890
The main contribution of this paper is the development of a novel attitude observer based on a triaxial high-grade rate gyro and single body-fixed vector measurements of a constant inertial vector, in contrast with typical solutions that require two of these vectors. The proposed structure consists in a cascade observer, where the angular velocity of the Earth around its own axis is extracted in the first block and the attitude is estimated in the second. The stability of the system as a whole is analyzed and the error dynamics are shown to be globally exponentially stable (GES). Simulation results are presented that illustrate the achievable performance of this solution. In a companion paper an alternative observer is proposed on the special orthogonal group and both solutions are compared.
In this paper a trajectory planner for n autonomous vehicles following a common leader is presented, with the planning being accomplished in real time and in a three dimensional setting. The trajectory planner is desi...
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ISBN:
(纸本)9781467360890
In this paper a trajectory planner for n autonomous vehicles following a common leader is presented, with the planning being accomplished in real time and in a three dimensional setting. The trajectory planner is designed such that n follower vehicles behave as n distinct points of a unique two dimensional trailer attached to a single leader vehicle. We prove that for a wide range of initial conditions the trailer reference frame converges to a unique solution, thus guaranteeing that each follower can plan its trajectory independently from its peers, thereby reducing the need for communications among vehicles. Additionally, convergence to a fixed formation of n + 1 vehicles with respect to the trailer reference frame is also guaranteed. Finally, we present bounds on the planned velocity and acceleration, which provide conditions for the feasibility of the planned trajectory. An experimental validation of the planner's behavior is presented with quadrotor vehicles, demonstrating the richness of the planned trajectories.
This paper proposes strategies for the driving and egress of a vehicle with a humanoid robot. To drive the vehicle, the RANSAC method was used to detect obstacles, and the Wagon model was used to control the steering ...
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ISBN:
(纸本)9781479968862
This paper proposes strategies for the driving and egress of a vehicle with a humanoid robot. To drive the vehicle, the RANSAC method was used to detect obstacles, and the Wagon model was used to control the steering and velocity of the vehicle with only a limited number of sensors which were installed on the humanoid robot. Additionally, a manual teleoperating method was used with the lane projection technique. For the egress motion, gain override and the Cartesian position/force control technique were used to interact with the vehicle structure. To overcome the disadvantages of a highly geared manipulator, a special technique was used that included modelled friction compensation and a non-complementary switching mode. DRC-HUBO+ used the proposed method to perform a vehicle driving and egress task in the DRC finals 2015.
This paper proposes a control architecture to achieve output synchronization of a group of heterogeneous LTI plants. To each plant, we associate a local controller that comprises a dynamic output feedback controller a...
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ISBN:
(纸本)9781467360890
This paper proposes a control architecture to achieve output synchronization of a group of heterogeneous LTI plants. To each plant, we associate a local controller that comprises a dynamic output feedback controller and a reference generator. The local dynamic output feedback controller is designed such that the output of the plant tracks the output of the reference generator. The reference generator includes an internal state that should be synchronized across all reference generators. The decision to broadcast this synchronization state to its neighbors is done by employing an event-triggered communication protocol. It is shown that, with the proposed control architecture, the solutions of the closed-loop system are globally bounded and that there exist positive lower bounds for the inter-event intervals generated the by event-triggered mechanism associated with the broadcast of synchronization states. A self-triggered implementation of the proposed event-triggered communication protocol is also presented.
The Widely scalable Mobile Underwater Sonar Technology (WiMUST) project is an H2020 Research and Innovation Action funded by the European Commission. The project aims at developing a system of cooperative Autonomous U...
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ISBN:
(纸本)9781479987375
The Widely scalable Mobile Underwater Sonar Technology (WiMUST) project is an H2020 Research and Innovation Action funded by the European Commission. The project aims at developing a system of cooperative Autonomous Underwater Vehicles (AUVs) for geotechnical surveying and geophysical exploration. The project will address underwater communication, acoustic distributed sensor array, mission planning and robot navigation, guidance and control issues. The paper gives an overview of the project objectives and methods.
There is considerable interest in reducing the number of sensors/beacons involved in underwater positioning/navigation systems since this has the potential to drastically reduce the costs and the time spent in deployi...
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There is considerable interest in reducing the number of sensors/beacons involved in underwater positioning/navigation systems since this has the potential to drastically reduce the costs and the time spent in deploying, calibrating, and recovering acoustic equipment at sea. Motivated by these considerations, we address the problem of single underwater target positioning based on acoustic range measurements between the target and a moving sensor at the sea surface. In particular, the goal of the present work is to compute optimal geometric trajectories for the surface sensor that will, in a well defined sense, maximize the range-related information available for underwater target positioning and tracking. To this effect, the Fisher Information Matrix and the maximization of its determinant are used to determine the sensor trajectory that yields the most accurate positioning of the target, while the latter describes a preplanned trajectory. It is shown that the optimal trajectory depends on the velocity of the sensor, the velocity and trajectory of the target, the sampling time between measurements, the measurement error model, and the number of measurements used to compute the FIM. Simulation examples illustrate the key results derived.
This paper addresses the problem of keeping an autonomous marine vehicle in a moving triangular formation by regulating its position with respect to two leader vehicles. The follower vehicle has no prior knowledge of ...
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This paper presents an improved method to teleoperate impedance of a robot based on surface electromyography (EMG) and test it experimentally. Based on a linear mapping between EMG amplitude and stiffness, an incremen...
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In this paper, we devise a controller that achieves global uniform exponential stabilization of linear systems while avoiding singular input constraints, that is, the proposed controller never crosses a given input va...
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ISBN:
(纸本)9781467360890
In this paper, we devise a controller that achieves global uniform exponential stabilization of linear systems while avoiding singular input constraints, that is, the proposed controller never crosses a given input value g. We show that it is possible to solve this problem using two linear controllers and an appropriate switching logic, which leads to a hybrid controller.
This paper proposes a general framework for structuring dynamic Particle Swarm populations and uses a conservation of function evaluations strategy to increase the convergence speed. The population structure is constr...
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ISBN:
(纸本)9789897580529
This paper proposes a general framework for structuring dynamic Particle Swarm populations and uses a conservation of function evaluations strategy to increase the convergence speed. The population structure is constructed by placing the particles on a 2-dimensional grid of nodes, where they interact and move according to simple rules. During the running time of the algorithm, the von Neumann neighborhood is used to decide which particles influence each other when updating their velocity and position. Each particle is updated in each time-step but they are evaluated only if there are other particles in their neighborhood. A set of experiments demonstrates that the dynamics imposed by the structure provides a more consistent and stable behavior throughout the test set when compared to standard topologies, while the conservation of evaluations significantly reduces the convergence speed of the algorithm. Furthermore, the working mechanisms of the proposed structure are very simple and, except for the size of the grid, they do not require parameters and tuning.
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