Robot path planning in unknown and dynamic environments is one of the hot topics in the field of robot control. The virtual force field (VFF) is an efficient path planning method for robot. However, there are some shortcomings of the traditional VFF based methods, such as the local minimum problem and the higher computational complexity, in dealing with the dynamic obstacle avoidance. In this paper, an improved VFF approach is proposed for the real-time robot path planning, where the environment is unknown and changing. An area ratio parameter is introduced into the proposed VFF based approach, where the size of the robot and obstacles are considered. Furthermore, a fuzzy control module is added, to deal with the problem of obstacle avoidance in dynamic environments, by adjusting the rotation angle of the robot. Finally, some simulation experiments are carried out to validate and demonstrate the efficiency of the proposed approach.

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This paper presents a kind of low power capacitance casting-chipping compound switch for reactive power compensation (RPC) equipment based on single-chip ATMEGA16L. Difficulties exist in RPC equipment design because there are problems of big surging and slow reaction when the contactor applied alone, and there are problems of big power consumption and low capability of the anti-interference when power electronic device applied alone. The proposed RPC equipment uses the parallel connection of thyristor and magnetic latching relay as the main loop switch. The switching process based on the concerted action between the magnetic latching relay and thyristor. The thyristor works only under the condition of voltage zero-cross. When the equipment switched on, the electric current is undertaken by the magnetic latching relay alone. This equipment has the advantages of low surging current, low power consumption, strong capability of anti-interference to harmonic and quick reaction of compensation. It can successfully achieve in the trouble shooting, trouble removal and trouble indicating. In the tests of switching 30Kvar capacitance, the surging current was 1.1 times of the peak of stable current. Good performance of this equipment is shown in the volume production and the application.

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