This paper describes a hierarchical fuzzy steering controller approach to local navigation of an autonomous sensor equipped mobile robots. Two goals are considered simultaneously: obstacle avoidance, so that the robot...
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This paper describes a hierarchical fuzzy steering controller approach to local navigation of an autonomous sensor equipped mobile robots. Two goals are considered simultaneously: obstacle avoidance, so that the robot is piloted safely in an unknown environment; and reaching an target point. A two-step approach to build a fuzzy system is presented. In the first stage signals are processed by conventional methods to get an output vector indicating the direction and the closeness of obstacles around. Stage two is a basic task steering controller, that is based on fuzzy logic. The modular structure of the first stage allows modifications on the robot. So there is no need for a redesign of the controller's architecture, when the controller is used in different applications. Adaptation to a new task is done simply by adjusting the controller to other conditions. Then the robustness of this controller is demonstrated in simulations by means of erroneous signals of the sensor modules. Finally the controller is used in combination with another basic task controller for 'Reaching an Aiming Point'. In a higher level a controller ascertains priority of the controllers and manages the resulting steering commands.
Wide scale deployment of wireless devices is making the spectrum a scarce resource. Joint communication and sensing (JC&S) and in-band full duplex (IBFD) communications provide opportunities of spectrum reuse. IBF...
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Wide scale deployment of wireless devices is making the spectrum a scarce resource. Joint communication and sensing (JC&S) and in-band full duplex (IBFD) communications provide opportunities of spectrum reuse. IBFD communication hardware requires high transmitter-to-receiver (TRx) isolation, making it shareable and reusable with mono-static continuous wave radar in JC&S context. On the other hand, design and development of beamforming phased arrays, required for communication coverage and radar spatial filtering, becomes challenging when a high TRx isolation assurance is required. This paper presents a solution in the form of antenna-duplexed passive beamformer usable for IBFD communication and mono-static continuous wave radars, mitigating two key challenges/requirements of JC&S hardware reuse in co-design approach - TRx isolation and beamforming capability. A beamformer using Butler matrix and a planar quasi-circulator are designed and optimized for X-band (centered at 10 GHz) providing up to 40 dB transmitter leakage suppression using primarily passive circuits.
In this paper we have addressed the problem of adopting in a combined way a genetic algorithm and the Hough transform for implementing an auto tracking method in a video conference system. By applying this method we h...
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In this paper we have addressed the problem of adopting in a combined way a genetic algorithm and the Hough transform for implementing an auto tracking method in a video conference system. By applying this method we have been able to track an object that moves slowly following quite parallel trajectories. The proposed algorithm considers just the shape of the object to be tracked and a priori known as a template, without taking into account other several characteristics of images like colour or texture. Because the implementation of Hough transform is a problem of maximising a function with particular constraints, and each run of evaluating Hough transform is time consuming, in this paper we have adopted a particular genetic algorithm to evaluate the rectangular region in which evaluate the Hough transform. The genetic algorithm used elitistic strategy, fitness sharing, mating restriction, adaptive rate of mutation and adaptive rate of cross-over with a double cross point. Moreover, in this paper, since the evaluation of Hough transform is very time consuming, we have addressed the strategy of dividing the whole scene in different shorter window in order to partition the evaluating load on parallel DSP.
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