The formation control of multiple unmanned aerial vehicles(multi-UAVs)has always been a research hotspot.Based on the straight line trajectory,a multi-UAVs target point assignment algorithm based on the assignment pro...The formation control of multiple unmanned aerial vehicles(multi-UAVs)has always been a research hotspot.Based on the straight line trajectory,a multi-UAVs target point assignment algorithm based on the assignment probability is proposed to achieve the shortest overall formation path of multi-UAVs with low complexity and reduce the energy consumption.In order to avoid the collision between UAVs in the formation process,the concept of safety ball is introduced,and the collision detection based on continuous motion of two time slots and the lane occupation detection after motion is proposed to avoid collision between UAVs.Based on the idea of game theory,a method of UAV motion form setting based on the maximization of interests is proposed,including the maximization of self-interest and the maximization of formation interest is proposed,so that multi-UAVs can complete the formation task quickly and reasonably with the linear trajectory assigned in advance.Finally,through simulation verification,the multi-UAVs target assignment algorithm based on the assignment probability proposed in this paper can effectively reduce the total path length,and the UAV motion selection method based on the maximization interests can effectively complete the task formation.展开更多
To accurately assess the performance of cooperative multiple packet reception （MPR） based on network-assisted diversity multiple access （NDMA）, non-ideal collision detection is introduced in ALLIANCES （ALLow impr...To accurately assess the performance of cooperative multiple packet reception （MPR） based on network-assisted diversity multiple access （NDMA）, non-ideal collision detection is introduced in ALLIANCES （ALLow improved access in the network via cooperation and energy savings）. To provide a unified anatysis frame- work, the length of cooperative transmission epoch is fixed to the detected collision order. The mathematical analysis of potential throughput （PTP） and potential packet loss rate （PPLR） are given under a pessimistic assumption and an optimistic assumption. According to the analysis of PTP and PPLR, threshold selection is done to optimize system performances, e.g. the optimal threshold should guarantee PTP to be maximum or guarantee PPLR to be minimum. In simulations, the thresholds are selected according to PTP under the pessimistic assumption. Simulation results show that the proposed cooperative MPR scheme can achieve higher throughput than NDMA and slotted ALOHA schemes.展开更多
Automated manufacturing system is characterized by flexibility. It aims at producing a variety of products with virtually no time loses to change over from one part to the next. In this paper, the Machining Process Si...Automated manufacturing system is characterized by flexibility. It aims at producing a variety of products with virtually no time loses to change over from one part to the next. In this paper, the Machining Process Simulator GMPS is introduced, which can be used as a supported environment for machining process. It can be executed off-line or on-line in manufacturing systems in order to predict the collisions of tool with machined workpieces, fixtures or pallets. First, the functional model of GMPS is described, then adopted critical techniques in the simulator are introduced. Finally, an application of GMPS in CIMS ERC of China is presented.展开更多
基金supported by the Basic Scientific Research Business Expenses of Central Universities(3072022QBZ0806)。
文摘The formation control of multiple unmanned aerial vehicles(multi-UAVs)has always been a research hotspot.Based on the straight line trajectory,a multi-UAVs target point assignment algorithm based on the assignment probability is proposed to achieve the shortest overall formation path of multi-UAVs with low complexity and reduce the energy consumption.In order to avoid the collision between UAVs in the formation process,the concept of safety ball is introduced,and the collision detection based on continuous motion of two time slots and the lane occupation detection after motion is proposed to avoid collision between UAVs.Based on the idea of game theory,a method of UAV motion form setting based on the maximization of interests is proposed,including the maximization of self-interest and the maximization of formation interest is proposed,so that multi-UAVs can complete the formation task quickly and reasonably with the linear trajectory assigned in advance.Finally,through simulation verification,the multi-UAVs target assignment algorithm based on the assignment probability proposed in this paper can effectively reduce the total path length,and the UAV motion selection method based on the maximization interests can effectively complete the task formation.
基金supported by the National Natural Science Foundation of China(60972039)the National High-Tech Research and Development Program of China(2009AA01Z241)+2 种基金the Key Grant and Basic Research Programs of Natural Science Fund for Higher Education of Jiangsu Province(06KJA51001)the Project Key Grant Research Programs of Natural Science Fund of Science and Technology Department of Jiangsu Province(BK2007729)the Natural Science Fund for Higher Education of Jiangsu Province(09KJB510012).
文摘To accurately assess the performance of cooperative multiple packet reception （MPR） based on network-assisted diversity multiple access （NDMA）, non-ideal collision detection is introduced in ALLIANCES （ALLow improved access in the network via cooperation and energy savings）. To provide a unified anatysis frame- work, the length of cooperative transmission epoch is fixed to the detected collision order. The mathematical analysis of potential throughput （PTP） and potential packet loss rate （PPLR） are given under a pessimistic assumption and an optimistic assumption. According to the analysis of PTP and PPLR, threshold selection is done to optimize system performances, e.g. the optimal threshold should guarantee PTP to be maximum or guarantee PPLR to be minimum. In simulations, the thresholds are selected according to PTP under the pessimistic assumption. Simulation results show that the proposed cooperative MPR scheme can achieve higher throughput than NDMA and slotted ALOHA schemes.
文摘Automated manufacturing system is characterized by flexibility. It aims at producing a variety of products with virtually no time loses to change over from one part to the next. In this paper, the Machining Process Simulator GMPS is introduced, which can be used as a supported environment for machining process. It can be executed off-line or on-line in manufacturing systems in order to predict the collisions of tool with machined workpieces, fixtures or pallets. First, the functional model of GMPS is described, then adopted critical techniques in the simulator are introduced. Finally, an application of GMPS in CIMS ERC of China is presented.
