A mathematical model was developed combining the dynamics of an Euler-Bernoulli beam, described by the assumed-mode method and hydraulic circuit dynamics. Only one matrix, termed drive Jacobian, was needed in the mode...A mathematical model was developed combining the dynamics of an Euler-Bernoulli beam, described by the assumed-mode method and hydraulic circuit dynamics. Only one matrix, termed drive Jacobian, was needed in the modeling of interaction between hydraulic circuit and flexible manipulator mechanism. Furthermore, a new robust controller based on mentioned above dynamic model was also considered to regulate both flexural vibrations and rigid body motion. The proposed controller combined sliding mode and backstepping techniques to deal with the nonlinear system with uncertainties. The sliding mode control was used to achieve an asymptotic joint angle and vibration regulation by providing a virtual force while the backstepping technique was used to regulate the spool position of a hydraulic valve to provide the required control force. Simulation results are presented to show the stabilizing effect and robustness of this control strategy.展开更多
The hydraulic flexible manipulator system is divided into two parts: flexible arm dynamics and hydraulic servomechanism, a driving Jacobian is derived to connect these two parts. Taking hydraulic actuator force as vir...The hydraulic flexible manipulator system is divided into two parts: flexible arm dynamics and hydraulic servomechanism, a driving Jacobian is derived to connect these two parts. Taking hydraulic actuator force as virtual input, a singular perturbed composite model is formulated and used to design composite controllers for the flexible link, in which the slow subsystem controller dominates the trajectory tracking, and then a fast controller is designed to damp out the vibration of the flexible structure. Moreover, the backstepping technique is applied to regulate the spool position of a hydraulic valve to provide the required force. Simulation results are provided to show the effectiveness of the presented approach.展开更多
针对具有参数不确定性、不匹配和匹配的时变扰动的电液执行器(electro‑hydraulic actuator,EHA)系统,提出了一种渐近跟踪控制策略.首先,构造了一个扩展状态观测器(extended state observer,ESO)获得对不匹配时变扰动的精确估计及补偿;该...针对具有参数不确定性、不匹配和匹配的时变扰动的电液执行器(electro‑hydraulic actuator,EHA)系统,提出了一种渐近跟踪控制策略.首先,构造了一个扩展状态观测器(extended state observer,ESO)获得对不匹配时变扰动的精确估计及补偿;该ESO通过在经典ESO中引入鲁棒自适应项,得到了渐近估计结果,降低了鲁棒增益选择的保守性.然后,设计一个鲁棒自适应项来估计匹配扰动的上界,以消除匹配时变扰动的影响.此外,自适应律用于估计参数不确定性.通过李雅普诺夫稳定性理论证明了跟踪误差能渐近收敛至零.最后,通过仿真和实验验证了所提控制策略的有效性.展开更多
文摘A mathematical model was developed combining the dynamics of an Euler-Bernoulli beam, described by the assumed-mode method and hydraulic circuit dynamics. Only one matrix, termed drive Jacobian, was needed in the modeling of interaction between hydraulic circuit and flexible manipulator mechanism. Furthermore, a new robust controller based on mentioned above dynamic model was also considered to regulate both flexural vibrations and rigid body motion. The proposed controller combined sliding mode and backstepping techniques to deal with the nonlinear system with uncertainties. The sliding mode control was used to achieve an asymptotic joint angle and vibration regulation by providing a virtual force while the backstepping technique was used to regulate the spool position of a hydraulic valve to provide the required control force. Simulation results are presented to show the stabilizing effect and robustness of this control strategy.
文摘The hydraulic flexible manipulator system is divided into two parts: flexible arm dynamics and hydraulic servomechanism, a driving Jacobian is derived to connect these two parts. Taking hydraulic actuator force as virtual input, a singular perturbed composite model is formulated and used to design composite controllers for the flexible link, in which the slow subsystem controller dominates the trajectory tracking, and then a fast controller is designed to damp out the vibration of the flexible structure. Moreover, the backstepping technique is applied to regulate the spool position of a hydraulic valve to provide the required force. Simulation results are provided to show the effectiveness of the presented approach.
文摘针对具有参数不确定性、不匹配和匹配的时变扰动的电液执行器(electro‑hydraulic actuator,EHA)系统,提出了一种渐近跟踪控制策略.首先,构造了一个扩展状态观测器(extended state observer,ESO)获得对不匹配时变扰动的精确估计及补偿;该ESO通过在经典ESO中引入鲁棒自适应项,得到了渐近估计结果,降低了鲁棒增益选择的保守性.然后,设计一个鲁棒自适应项来估计匹配扰动的上界,以消除匹配时变扰动的影响.此外,自适应律用于估计参数不确定性.通过李雅普诺夫稳定性理论证明了跟踪误差能渐近收敛至零.最后,通过仿真和实验验证了所提控制策略的有效性.
