Load-sensing systems use a centralized power source for energy supply and multiway valves for flow distribution and suffer from excessive throttling losses and low energy efficiency.Pump-controlled systems adopt volum...Load-sensing systems use a centralized power source for energy supply and multiway valves for flow distribution and suffer from excessive throttling losses and low energy efficiency.Pump-controlled systems adopt volumetric control methods to eliminate throttling losses.However,pump-controlled multi-actuator systems require excessive installed power.To address these issues,by combining the respective advantages of valve-and pump-controlled technologies,an open-closed circuit integrated pump-valve collaborative drive multi-actuator system consisting of pump-and valve-controlled units is proposed.The pump-controlled units manage the individual actuator motions,whereas the valve-controlled unit enhances the driving power of the pump-controlled units.In addition,to optimize the operation characteristics and energy consumption,a four-quadrant control strategy and an ultralow-pressure loss control strategy were proposed.Several experiments were conducted to evaluate the working performance of the proposed system and the load-sensing system under different working conditions.Experimental results demonstrated that the proposed system exhibited satisfactory velocity control characteristics.Compared with the traditional load-sensing system,the proposed system reduced throttling losses by 90.4−94.4%and energy consumption by 45.9−50.0%.Additionally,only 22.8%of the total energy consumption was attributed to the pump-controlled units,with the remainder provided by the valve-controlled unit.Compared with the traditional pump-controlled multi-actuator system,the proposed system achieved a 29.4%reduction in installed power,thereby lowering the system installed power and costs.This paper presents an electrohydraulic multi-actuator drive method that combines high energy efficiency and high power density and is suitable for electric construction machinery and other heavy equipment with multiple actuators.展开更多
As low-cost and highly autonomous ocean observation platforms,underwater gliders encounter risks during their launch and recovery,especially when coordinating multi-glider deployments.This work focuses on cooperative ...As low-cost and highly autonomous ocean observation platforms,underwater gliders encounter risks during their launch and recovery,especially when coordinating multi-glider deployments.This work focuses on cooperative path planning of an underwater glider fleet with simultaneous launch and recovery to enhance the autonomy of sampling and reduce deployment risks.Specifically,the gliders collaborate to achieve sampling considering the specified routines of interest.The overall paths to be planned are divided into four rectangular parts with the same starting point,and each glider is assigned a local sampling route.A clipped-oriented line-of-sight algorithm is proposed to ensure the coverage of the desired edges.The pitch angle of the glider is selected as the optimizing parameter to coordinate the overall progress considering the susceptibility of gliders to currents and the randomness of paths produced by complex navigational strategies.Therefore,a multi-actuation deep-Q network algorithm is proposed to ensure simultaneous launch and recovery.Simulation results demonstrate the acceptable effectiveness of the proposed method.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.52075358).
文摘Load-sensing systems use a centralized power source for energy supply and multiway valves for flow distribution and suffer from excessive throttling losses and low energy efficiency.Pump-controlled systems adopt volumetric control methods to eliminate throttling losses.However,pump-controlled multi-actuator systems require excessive installed power.To address these issues,by combining the respective advantages of valve-and pump-controlled technologies,an open-closed circuit integrated pump-valve collaborative drive multi-actuator system consisting of pump-and valve-controlled units is proposed.The pump-controlled units manage the individual actuator motions,whereas the valve-controlled unit enhances the driving power of the pump-controlled units.In addition,to optimize the operation characteristics and energy consumption,a four-quadrant control strategy and an ultralow-pressure loss control strategy were proposed.Several experiments were conducted to evaluate the working performance of the proposed system and the load-sensing system under different working conditions.Experimental results demonstrated that the proposed system exhibited satisfactory velocity control characteristics.Compared with the traditional load-sensing system,the proposed system reduced throttling losses by 90.4−94.4%and energy consumption by 45.9−50.0%.Additionally,only 22.8%of the total energy consumption was attributed to the pump-controlled units,with the remainder provided by the valve-controlled unit.Compared with the traditional pump-controlled multi-actuator system,the proposed system achieved a 29.4%reduction in installed power,thereby lowering the system installed power and costs.This paper presents an electrohydraulic multi-actuator drive method that combines high energy efficiency and high power density and is suitable for electric construction machinery and other heavy equipment with multiple actuators.
基金supported by the National Natural Science Foundation of China(No.51909252)the Fundamental Research Funds for the Central Universities(No.202061004)This work is also partly supported by the China Scholar Council.
文摘As low-cost and highly autonomous ocean observation platforms,underwater gliders encounter risks during their launch and recovery,especially when coordinating multi-glider deployments.This work focuses on cooperative path planning of an underwater glider fleet with simultaneous launch and recovery to enhance the autonomy of sampling and reduce deployment risks.Specifically,the gliders collaborate to achieve sampling considering the specified routines of interest.The overall paths to be planned are divided into four rectangular parts with the same starting point,and each glider is assigned a local sampling route.A clipped-oriented line-of-sight algorithm is proposed to ensure the coverage of the desired edges.The pitch angle of the glider is selected as the optimizing parameter to coordinate the overall progress considering the susceptibility of gliders to currents and the randomness of paths produced by complex navigational strategies.Therefore,a multi-actuation deep-Q network algorithm is proposed to ensure simultaneous launch and recovery.Simulation results demonstrate the acceptable effectiveness of the proposed method.
