双电机驱动伺服系统消隙及同步控制方法

发布时间：2018-01-22 01:11

本文关键词： 永磁同步电机双电机驱动消隙滑模控制转速同步控制　出处：《天津工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：双电机驱动齿轮传动系统具有输出功率大、结构紧凑、效率高、成本低等优点,因此在重载场合得到了广泛应用。对于高精度、高速随动系统,伺服电机驱动负载频繁换向,难以克服由啮合间隙造成的传动误差和回程误差,严重影响伺服系统的传动精度和系统性能。此外,当系统中两台电机共同驱动负载时,由于实际电机参数不一致、传动链抗扭特性差异、各电机受到扰动不同等因素,都会导致驱动电机间出现速度同步误差,极易引发差速振荡现象,严重时会造成单台电机过载,甚至机械轴断裂,为此必须采取一定的控制方法,保证两台驱动电机的速度同步。为消除齿轮啮合间隙对系统造成的影响,本文建立了双永磁同步电机驱动伺服系统含齿隙时的动力学模型,分析了齿轮啮合原理,设计了基于变偏置力矩的双电机消隙控制策略,对两台电机的输出转矩进行联动控制,始终保证至少有一个小齿轮与大齿轮啮合,使大齿轮无法在齿隙中自由摆动,降低齿隙对系统的影响,从而精确传递力矩、速度和位移。传统双PI并行控制下,当其中一台电机受到负载扰动时,两台电机之间将出现较大的速度同步误差,由于两台电机之间是齿轮刚性连接,极易引发差速振荡现象,严重时还会造成单台电机过载甚至机械轴断裂。针对该问题,本文结合滑模控制算法和交叉耦合控制结构,提出一种转速同步控制策略。该控制策略采用一种积分型滑模速度控制器来提高电机的抗扰性,并增强了两台电机之间的速度耦合作用,通过将两台电机之间的转速差信息反馈到两台电机的电流环,来快速补偿两台电机之间的速度同步误差。同时,本文研究了同步耦合系数的取值对系统同步性能的影响,通过仿真和实验选取了同步耦合系数的最优值,增强了系统的抗负载扰动能力,提升了系统的转速同步性能。最后,搭建了双电机驱动伺服系统的硬件实验平台,编写了实验程序,分别对传统双PI并行控制和转速同步控制策略进行了实验验证。实验结果表明,当系统受到负载扰动时,转速同步控制策略不仅可以降低转速跟踪误差和同步误差,同时能够缩短系统的恢复时间,有效提升系统的同步性能,降低差速振荡风险。
[Abstract]:The double motor drive gear drive system has the advantages of high output power, compact structure, high efficiency, low cost and so on, so it has been widely used in heavy load situations. The servo motor drives the load to change direction frequently, it is difficult to overcome the transmission error and the return range error caused by the meshing clearance, which seriously affects the drive precision and the system performance of the servo system. When the two motors in the system drive the load together, because the actual motor parameters are not consistent, the torsional characteristics of the transmission chain are different, and the motor is disturbed by different factors, which will lead to the speed synchronization error between the drive motors. It is easy to cause differential oscillation, which can lead to overload of single motor and even fracture of mechanical shaft when it is serious. Therefore, certain control methods must be adopted. In order to eliminate the influence of gear meshing clearance on the system, the dynamic model of double permanent magnet synchronous motor drive servo system with tooth gap is established in this paper. The gear-meshing principle is analyzed, and the anti-gap control strategy of double-motor based on variable offset torque is designed. The output torque of two motors is controlled by linkage, which always ensures that at least one pinion and big gear are engaged. The large gear is unable to swing freely in the gear gap, and the influence of the gear gap on the system is reduced. Thus, the torque, velocity and displacement can be accurately transferred. Under the traditional dual Pi parallel control, one of the motors is disturbed by load. There will be a large speed synchronization error between the two motors. Due to the rigid connection between the two motors, it is easy to cause differential oscillation. In order to solve this problem, the sliding mode control algorithm and cross-coupling control structure are combined to solve the problem. A synchronous speed control strategy is proposed, which uses an integral sliding mode speed controller to improve the immunity of the motor and enhance the speed coupling between the two motors. The information of the speed difference between the two motors is fed back to the current loop of the two motors to compensate the speed synchronization error between the two motors quickly. At the same time. In this paper, the effect of the synchronous coupling coefficient on the synchronization performance of the system is studied. The optimal value of the synchronous coupling coefficient is selected by simulation and experiment, and the anti-load disturbance ability of the system is enhanced. The speed synchronization performance of the system is improved. Finally, the hardware experiment platform of dual-motor drive servo system is built, and the experimental program is compiled. The experimental results show that when the system is disturbed by the load, the traditional dual Pi parallel control and rotational speed synchronization control strategy are verified by experiments. The speed synchronization control strategy can not only reduce the speed tracking error and synchronization error, but also shorten the recovery time of the system, effectively improve the synchronization performance of the system and reduce the risk of differential oscillation.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM921.541

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