Marine resource exploitation and marine cargo transportation were increasingly frequent. Due to the impact of the marine environment, ships or platforms were affected. In this paper, a servo electric cylinder was used...Marine resource exploitation and marine cargo transportation were increasingly frequent. Due to the impact of the marine environment, ships or platforms were affected. In this paper, a servo electric cylinder was used as a wave compensation actuator to design a wave compensation system. The laser sensor was used to measure the displacement in the direction of the heave platform, and the obtained displacement was applied to the wave compensation in the heave direction to verify the feasibility of the compensation system.展开更多
In order to validate the simulation model and develop heave compensation control strategy,heave compensation model tests were performed.The model test installation includes themining ship motion simulator,the heave co...In order to validate the simulation model and develop heave compensation control strategy,heave compensation model tests were performed.The model test installation includes themining ship motion simulator,the heave compensation system,the lifting pipe simulator,the buffer simulator and the water pool.The tests ofmining ship motion simulator show that it is able to perform under the predetermined attitude path smoothly and can meet the requirements of themining ship motions.The heave compensation effect is more than 60% under random wave and the goal is set to be 50%.The model test results indicate that this heave compensation system is effective and feasible.展开更多
The vessel heave motion caused by wave action increases the difficulty of installing offshore wind equipment.On-board wave heave compensation devices have therefore become increasingly critical in ensuring the stabili...The vessel heave motion caused by wave action increases the difficulty of installing offshore wind equipment.On-board wave heave compensation devices have therefore become increasingly critical in ensuring the stability and safety of the gangway and working platform.This study accordingly improves the compensation effect of such devices by developing a wave heave compensation model and designing an optimized backstepping control method.First,a model of the compensation system including the servo motor and electric cylinder is established by using the mechanism method.Second,a backstepping control method is designed to track the vessel heave motion,and particle swarm optimization is applied to optimize the control parameters.Finally,MATLAB/Simulink is used to simulate the application of the optimized backstepping controller,then regular and irregular heave motions are applied as input to a Stewart platform to evaluate the effectiveness of the control method.The experimental results show that the compensation efficiency provided by the proposed optimized backstepping control method is larger than 75.0%.展开更多
Active heave compensation systems are usually employed in offshore and deep-sea operations to reduce the adverse impact of unexpected vessel’s vertical motion on the response of underwater instruments.This paper pres...Active heave compensation systems are usually employed in offshore and deep-sea operations to reduce the adverse impact of unexpected vessel’s vertical motion on the response of underwater instruments.This paper presents a control strategy for an active heave compensation system consisting of an electro-hydraulic system driven by a double rod actuator,which is subjected to parametric uncertainties and unmeasured environmental disturbances.Adaptive observer and discontinuous projection type updating law with bounded adaption rate are presented firstly to estimate the uncertain system parameters.Then a similar estimation algorithm is designed by using a multiple delayed version of the system to enhance the performance of parameter observation.A reduced order observer is also introduced to estimate unknown wave disturbances.Using the obtained uncertainty information,the resulting control development and stability analysis are implemented based on the Lyapunov’s direct method and back-stepping technique.The proposed controller guarantees the heave compensation error convergent to a bounded neighborhood around the origin.Simulations illustrate the effectiveness of the proposed control system.展开更多
A passive heave compensator is designed to enhance the operation safety of a 4.5 km remotely operated vehicle (ROV).This paper proposes a novel idea of designing a compensator with relatively low natural period to opt...A passive heave compensator is designed to enhance the operation safety of a 4.5 km remotely operated vehicle (ROV).This paper proposes a novel idea of designing a compensator with relatively low natural period to optimize gas volume and while adding a special device to remove the problem of ineffectiveness and resonance in long seas.Numerical simulations are done based on serious dynamic model of the whole system,including the compensator,the umbilical tether and the vehicle,solved by the fourth-order Runge-Kutta scheme.The compensator provides great attenuation of motion and tension in most sea states.As the working depth increases,the system natural period decreases,resulting in the occurrence of risk of resonance.By regulating the system damping,the compensator can be effective in these situations.展开更多
文摘Marine resource exploitation and marine cargo transportation were increasingly frequent. Due to the impact of the marine environment, ships or platforms were affected. In this paper, a servo electric cylinder was used as a wave compensation actuator to design a wave compensation system. The laser sensor was used to measure the displacement in the direction of the heave platform, and the obtained displacement was applied to the wave compensation in the heave direction to verify the feasibility of the compensation system.
基金Project(50675226) supported by the National Natural Science Foundation of China Project(DYXM-115-04-02-01) supported by the Eleventh Five-Year Plan of China
文摘In order to validate the simulation model and develop heave compensation control strategy,heave compensation model tests were performed.The model test installation includes themining ship motion simulator,the heave compensation system,the lifting pipe simulator,the buffer simulator and the water pool.The tests ofmining ship motion simulator show that it is able to perform under the predetermined attitude path smoothly and can meet the requirements of themining ship motions.The heave compensation effect is more than 60% under random wave and the goal is set to be 50%.The model test results indicate that this heave compensation system is effective and feasible.
基金supported by the National Natural Science Foundation of China(Grant No.62073213).
文摘The vessel heave motion caused by wave action increases the difficulty of installing offshore wind equipment.On-board wave heave compensation devices have therefore become increasingly critical in ensuring the stability and safety of the gangway and working platform.This study accordingly improves the compensation effect of such devices by developing a wave heave compensation model and designing an optimized backstepping control method.First,a model of the compensation system including the servo motor and electric cylinder is established by using the mechanism method.Second,a backstepping control method is designed to track the vessel heave motion,and particle swarm optimization is applied to optimize the control parameters.Finally,MATLAB/Simulink is used to simulate the application of the optimized backstepping controller,then regular and irregular heave motions are applied as input to a Stewart platform to evaluate the effectiveness of the control method.The experimental results show that the compensation efficiency provided by the proposed optimized backstepping control method is larger than 75.0%.
基金the National High Technology Research and Development Program (863) of China (No.2007AA09Z215)the International Seabed Area Research and Exploration (the Eleventh Five-Year) Program of COMRA(No.DYXM-115-03-09-05)+1 种基金the National Natural Science Foundation of China (No.51009091)the Research Fund for the Doctoral Program of Higher Education of China (No.20100073120016)
文摘Active heave compensation systems are usually employed in offshore and deep-sea operations to reduce the adverse impact of unexpected vessel’s vertical motion on the response of underwater instruments.This paper presents a control strategy for an active heave compensation system consisting of an electro-hydraulic system driven by a double rod actuator,which is subjected to parametric uncertainties and unmeasured environmental disturbances.Adaptive observer and discontinuous projection type updating law with bounded adaption rate are presented firstly to estimate the uncertain system parameters.Then a similar estimation algorithm is designed by using a multiple delayed version of the system to enhance the performance of parameter observation.A reduced order observer is also introduced to estimate unknown wave disturbances.Using the obtained uncertainty information,the resulting control development and stability analysis are implemented based on the Lyapunov’s direct method and back-stepping technique.The proposed controller guarantees the heave compensation error convergent to a bounded neighborhood around the origin.Simulations illustrate the effectiveness of the proposed control system.
基金the National High Technology Research and Development Program (863) of China(No. 2008AA092301-1)the National Natural Science Foundation of China(No. 50909061)the PH. D. Programs Foundation of Ministry of Education of China(No. 20070248103)
文摘A passive heave compensator is designed to enhance the operation safety of a 4.5 km remotely operated vehicle (ROV).This paper proposes a novel idea of designing a compensator with relatively low natural period to optimize gas volume and while adding a special device to remove the problem of ineffectiveness and resonance in long seas.Numerical simulations are done based on serious dynamic model of the whole system,including the compensator,the umbilical tether and the vehicle,solved by the fourth-order Runge-Kutta scheme.The compensator provides great attenuation of motion and tension in most sea states.As the working depth increases,the system natural period decreases,resulting in the occurrence of risk of resonance.By regulating the system damping,the compensator can be effective in these situations.
