3 D roll-forming for high strength steel sheets is a new technology at present.Double racks gear 3D roll forming machine developed by our research group can be used to perform variable cross section roll forming for h...3 D roll-forming for high strength steel sheets is a new technology at present.Double racks gear 3D roll forming machine developed by our research group can be used to perform variable cross section roll forming for high strength steel.In the paper,a dynamic model of 8-DOF double rack gear 3D roll-forming machine is established by the method of Lagrange equation.The expression of the angle acceleration of the system response is obtained by solving the dynamic equations.Through an actual engineering example,the dynamical characters of the 3D roll forming machine are revealed.The results can support the design of 3D roll forming machine.Meanwhile,the research will play an active role in the development of control system.展开更多
Significant research interest has recently been attracted to the study of bipedal robots due to the wide variety of their potential applications.In reality,bipedal robots are often required to perform gait transitions...Significant research interest has recently been attracted to the study of bipedal robots due to the wide variety of their potential applications.In reality,bipedal robots are often required to perform gait transitions to achieve flexible walking.In this paper,we consider the gait transition of a five-link underactuated three-dimensional(3 D)bipedal robot,and propose a two-layer control strategy.The strategy consists of a unique,event-based,feedback controller whose feedback gain in each step is updated by an adaptive control law,and a transition controller that guides the robot from the current gait to a neighboring point of the target gait so that the state trajectory can smoothly converge to the target gait.Compared with previous works,the transition controller is parameterized and its control parameters are obtained by solving an optimization problem to guarantee the physical constraints in the transition process.Finally,the effectiveness of the control strategy is illustrated on the underactuated 3 D bipedal robot.展开更多
基金Supported by the National Science and Technology Supporting Plan Projects of China （No.2011BAG03B03）.
文摘3 D roll-forming for high strength steel sheets is a new technology at present.Double racks gear 3D roll forming machine developed by our research group can be used to perform variable cross section roll forming for high strength steel.In the paper,a dynamic model of 8-DOF double rack gear 3D roll-forming machine is established by the method of Lagrange equation.The expression of the angle acceleration of the system response is obtained by solving the dynamic equations.Through an actual engineering example,the dynamical characters of the 3D roll forming machine are revealed.The results can support the design of 3D roll forming machine.Meanwhile,the research will play an active role in the development of control system.
基金Project supported by the National Natural Science Foundation of China(Nos.91748126,11772292,and 51521064)
文摘Significant research interest has recently been attracted to the study of bipedal robots due to the wide variety of their potential applications.In reality,bipedal robots are often required to perform gait transitions to achieve flexible walking.In this paper,we consider the gait transition of a five-link underactuated three-dimensional(3 D)bipedal robot,and propose a two-layer control strategy.The strategy consists of a unique,event-based,feedback controller whose feedback gain in each step is updated by an adaptive control law,and a transition controller that guides the robot from the current gait to a neighboring point of the target gait so that the state trajectory can smoothly converge to the target gait.Compared with previous works,the transition controller is parameterized and its control parameters are obtained by solving an optimization problem to guarantee the physical constraints in the transition process.Finally,the effectiveness of the control strategy is illustrated on the underactuated 3 D bipedal robot.
