Li Xiaopeng, Shang Dongyang, Li Haiyang, Li Fanjie
School of Mechanical Engineering and Automation, Northeastern University, Shenyang, China.
Sci Prog. 2020 Jul-Sep;103(3):36850420950130. doi: 10.1177/0036850420950130.
A typical serial manipulator consists of a servo motor, a serial mechanism and an independent joint placed between the motor and the serial mechanism. Both the time-varying characteristics of the inertia of the serial mechanism and the flexibility characteristics of the independent joint are widely found in serial manipulator servo drive systems. These two characteristics not only increase the resonance magnitude of serial manipulators, but also affect the dynamic characteristics of the system. In order to obtain a stable output speed of serial manipulators, the variable parameters of a PI control strategy is applied to a serial manipulator servo drive system. Firstly, dynamic model of a serial manipulator servo drive system is established based on a two-inertia system. Then the transfer function from motor speed to motor electromagnetic torque is derived by the state-space equation. Furthermore, the parameters of the PI controller are designed and optimized utilizing three different pole assignment strategies with the identical radius, the identical damping coefficients, and the identical real parts. The results indicate that a serial manipulator servo drive system can obtain good dynamic characteristics by selecting parameters of the PI controller appropriately.
典型的串联机械手由一个伺服电机、一个串联机构以及置于电机和串联机构之间的独立关节组成。串联机构的惯量时变特性和独立关节的柔性特性在串联机械手伺服驱动系统中广泛存在。这两个特性不仅会增大串联机械手的共振幅度，还会影响系统的动态特性。为了获得串联机械手稳定的输出速度，将PI控制策略的可变参数应用于串联机械手伺服驱动系统。首先，基于双惯量系统建立串联机械手伺服驱动系统的动态模型。然后通过状态空间方程推导从电机速度到电机电磁转矩的传递函数。此外，利用具有相同半径、相同阻尼系数和相同实部的三种不同极点配置策略对PI控制器的参数进行设计和优化。结果表明，通过适当选择PI控制器的参数，串联机械手伺服驱动系统能够获得良好的动态特性。
