This study introduces a wheeled robot platform with jumping ability.To realize jump movement,a twisted string lever mechanism is used,which is characterized by its compactness and variable gear ratio.Based on robot mo...This study introduces a wheeled robot platform with jumping ability.To realize jump movement,a twisted string lever mechanism is used,which is characterized by its compactness and variable gear ratio.Based on robot modeling and parameter calculation,the twisted string actuator shows its advantage when applied to situations such as jumping of robots,where explosiveness of output force matters.In this study,a wheeled bipedal robot equipped with the twisted string actuator is designed and fabricated.It weighs 16.0 kg and can perform jumps when it encounters obstacles.The prototype can jump up to a stage with a maximum height of 1.0 m using electric power,which is approximately 1.5 times the height of its stretched legs.展开更多
Based on the mechanical model of an elastic rod,a new trajectory design method was established.The advantages of the suspender line trajectory in reducing drag and torsion were compared,and the main controlling factor...Based on the mechanical model of an elastic rod,a new trajectory design method was established.The advantages of the suspender line trajectory in reducing drag and torsion were compared,and the main controlling factors of drag and torque and their influence rules were analyzed.Research shows that the suspender line trajectory reduces drag and torque more effectively than the conventional trajectory in a certain parameter interval and has more controllable parameters than that of the catenary trajectory.The main factors affecting the drag reduction and torque reduction of the suspender line trajectory include the friction coefficient,vertical distance,horizontal distance,and deviation angle at the initial point in the suspended section.The larger the friction coefficient and deviation angle,the less the drag reduction and torque reduction.The suspender line trajectory has the best drag reduction effect when the horizontal and vertical distances are more than 3000 m and the ratio is close to 1.5.The drag in sliding drilling can be reduced up to 60%,and the torque in rotary drilling can be reduced by a maximum of 40%.Therefore,the trajectory design of the suspender line has unique application prospects in deep extended-reach wells.展开更多
Background Coiled tubing operation is a high-quality operation method that considers both cost and efficiency in current oil and gas well operations.There is a significant difference between the calculation and predic...Background Coiled tubing operation is a high-quality operation method that considers both cost and efficiency in current oil and gas well operations.There is a significant difference between the calculation and prediction before operation and the actual operation.The reason is that the complex wellbore trajectory makes it difficult to evaluate the contact state between coiled tubing and wellbore,resulting in a significant error in the pipe string mechanics calculation and analysis.Methods In this study,a digital twin-based method for continuous tubing wear modelling is proposed.Firstly,the digital twin unit of continuous tubing-wellbore is constructed to achieve the fusion modelling of three types of information,namely structure,physical field and material,of the micro-element well section.On this basis,a feedbackcorrected contact algorithm is introduced to dynamically identify and correct the contact state of continuous tubing under different downhole running trajectories.By constructing a spatial and temporal two-dimensional digital twin of the continuous tubing operation process,the accurate positioning and historical state tracing of the tubing entity in the complex downhole environment are realised.Results The research results show that the digital twin coiled tubing and contact algorithm can effectively predict the contact state of coiled tubing operations;the verification model shows that the contact algorithm can accurately analyze the contact state of different well trajectories.Conclusions The digital twin of the coiled tubing operation structure and its contact algorithm can effectively solve the problem of deterministic friction state in the process of mechanical calculation of the tubing string,which has important guiding significance and engineering value for the mechanical calculation and operation safety analysis of coiled tubing operation.展开更多
基金Project supported by the Grant from Zhejiang Lab,China(No.2019KE0AD01)。
文摘This study introduces a wheeled robot platform with jumping ability.To realize jump movement,a twisted string lever mechanism is used,which is characterized by its compactness and variable gear ratio.Based on robot modeling and parameter calculation,the twisted string actuator shows its advantage when applied to situations such as jumping of robots,where explosiveness of output force matters.In this study,a wheeled bipedal robot equipped with the twisted string actuator is designed and fabricated.It weighs 16.0 kg and can perform jumps when it encounters obstacles.The prototype can jump up to a stage with a maximum height of 1.0 m using electric power,which is approximately 1.5 times the height of its stretched legs.
基金Supported by the National Science and Technology Major Project(2016ZX05060-014)PetroChina Major Science and Technology Project(ZD2019-183-005)。
文摘Based on the mechanical model of an elastic rod,a new trajectory design method was established.The advantages of the suspender line trajectory in reducing drag and torsion were compared,and the main controlling factors of drag and torque and their influence rules were analyzed.Research shows that the suspender line trajectory reduces drag and torque more effectively than the conventional trajectory in a certain parameter interval and has more controllable parameters than that of the catenary trajectory.The main factors affecting the drag reduction and torque reduction of the suspender line trajectory include the friction coefficient,vertical distance,horizontal distance,and deviation angle at the initial point in the suspended section.The larger the friction coefficient and deviation angle,the less the drag reduction and torque reduction.The suspender line trajectory has the best drag reduction effect when the horizontal and vertical distances are more than 3000 m and the ratio is close to 1.5.The drag in sliding drilling can be reduced up to 60%,and the torque in rotary drilling can be reduced by a maximum of 40%.Therefore,the trajectory design of the suspender line has unique application prospects in deep extended-reach wells.
基金supported by the Scientific Research Program Funded by Shaanxi Provincial Education Department under contact No.21JP096.
文摘Background Coiled tubing operation is a high-quality operation method that considers both cost and efficiency in current oil and gas well operations.There is a significant difference between the calculation and prediction before operation and the actual operation.The reason is that the complex wellbore trajectory makes it difficult to evaluate the contact state between coiled tubing and wellbore,resulting in a significant error in the pipe string mechanics calculation and analysis.Methods In this study,a digital twin-based method for continuous tubing wear modelling is proposed.Firstly,the digital twin unit of continuous tubing-wellbore is constructed to achieve the fusion modelling of three types of information,namely structure,physical field and material,of the micro-element well section.On this basis,a feedbackcorrected contact algorithm is introduced to dynamically identify and correct the contact state of continuous tubing under different downhole running trajectories.By constructing a spatial and temporal two-dimensional digital twin of the continuous tubing operation process,the accurate positioning and historical state tracing of the tubing entity in the complex downhole environment are realised.Results The research results show that the digital twin coiled tubing and contact algorithm can effectively predict the contact state of coiled tubing operations;the verification model shows that the contact algorithm can accurately analyze the contact state of different well trajectories.Conclusions The digital twin of the coiled tubing operation structure and its contact algorithm can effectively solve the problem of deterministic friction state in the process of mechanical calculation of the tubing string,which has important guiding significance and engineering value for the mechanical calculation and operation safety analysis of coiled tubing operation.
