To provide a suitable model for AUV simulation and control purposes, a general nonlinear dynamic model including a novel thruster hydrodynamics model was derived. Based on the modeling method, the "AUV-XX" s...To provide a suitable model for AUV simulation and control purposes, a general nonlinear dynamic model including a novel thruster hydrodynamics model was derived. Based on the modeling method, the "AUV-XX" simulation platform was established to carry out fundamental tests on its motion characteristics, stability, and controllability. A motion control strategy consisting of both position and speed control in a horizontal plane was designed for different task assignments of underwater vehicles. Combined control of heave and pitch was adopted to compensate for the reduction of vertical tunnel thrusters when the vehicle is moving at a high speed. An improved S-surface controller based on the capacitor plate model was developed with flexible gain selections made possible by different forms of restricting the error and changing the rate of the error. Simulation results show that the derived general mathematical model together with simulation platform can provide a test bed for fundamental tests of motion control. Additionally, the capacitor plate model S-surface control shows a good performance in guiding the vehicle to achieve the desired position and speed with sufficient accuracy.展开更多
In the 21st century, especially after the accession to WTO, Construction project bidding price formation mechanism is the main characteristics of the market price of the Construction project is divided in a unified, u...In the 21st century, especially after the accession to WTO, Construction project bidding price formation mechanism is the main characteristics of the market price of the Construction project is divided in a unified, uniform measurement unit, unified in terms of engineering and consumption of fixed rules on the basis of the implementation of market, competition fees.The first to be carried out not only the financial decision-making, corporate contractors in accordance with the different ways, according to market conditions, its technology, economic strength, through the financial decision-making self-quotation. Second, it is necessary to exercise effective control, both the Construction project bidding price by the form of the contract price is fixed.By design, material procurement, construction management on the implementation of bidding for the effective control of prices.展开更多
基金the National Science Foundation under Grant No.50879014,No.50909025
文摘To provide a suitable model for AUV simulation and control purposes, a general nonlinear dynamic model including a novel thruster hydrodynamics model was derived. Based on the modeling method, the "AUV-XX" simulation platform was established to carry out fundamental tests on its motion characteristics, stability, and controllability. A motion control strategy consisting of both position and speed control in a horizontal plane was designed for different task assignments of underwater vehicles. Combined control of heave and pitch was adopted to compensate for the reduction of vertical tunnel thrusters when the vehicle is moving at a high speed. An improved S-surface controller based on the capacitor plate model was developed with flexible gain selections made possible by different forms of restricting the error and changing the rate of the error. Simulation results show that the derived general mathematical model together with simulation platform can provide a test bed for fundamental tests of motion control. Additionally, the capacitor plate model S-surface control shows a good performance in guiding the vehicle to achieve the desired position and speed with sufficient accuracy.
文摘In the 21st century, especially after the accession to WTO, Construction project bidding price formation mechanism is the main characteristics of the market price of the Construction project is divided in a unified, uniform measurement unit, unified in terms of engineering and consumption of fixed rules on the basis of the implementation of market, competition fees.The first to be carried out not only the financial decision-making, corporate contractors in accordance with the different ways, according to market conditions, its technology, economic strength, through the financial decision-making self-quotation. Second, it is necessary to exercise effective control, both the Construction project bidding price by the form of the contract price is fixed.By design, material procurement, construction management on the implementation of bidding for the effective control of prices.
