Driving Mechanism and Control of Ultrasonic Motor

将估计的驱动转矩与实际负载转矩进行比较。该估计基于原始驱动模型。考虑转子和定子两面翘曲的详细研究尚未展开。此外，众所周知，当电机驱动时，会发出刺耳的声音。利用新研制的测量系统，对转子的弹性变形、齿的垂直振动和水平振动以及转速进行了精确测量。实验结果表明：(a)随着预紧力的增大，定子各齿与转子的接触程度按接近程度排序。(b)齿在转子附近的弹性变形大于远离转子的弹性变形。(c)它们牙齿的周向速度几乎相同。(d)在特定牙齿上测量频率为4.9千赫的尖叫振动。USM在恒速驱动中存在两个问题，一是运行过程中温升的影响，二是定子和转子初始变形的影响。自适应控制方法已被应用于实现恒速驱动，但系统地设计控制器比较困难。在本研究中，采用H_*重复控制方法：(a)设计了H_*速度控制系统，使其对温度波动的影响具有鲁棒稳定性。(b)附加了重复补偿器以提高抗扰特性。通过控制实验验证了重复补偿器的有效性。

The estimated driving torque is compared with the actual load torque. The estimation is based on a primitive driving model. The detailed studies, considering warp of both surfaces of rotor and stator, have not been developed yet. Moreover, it is well known that a squealing sound occurs while the motor is driving.Elastic deformation of the rotor, vertical and horizontal vibrations of teeth and rotary speed were measured precisely by using a newly developed measuring system. The experiment shows the followings :(a) Each tooth of the stator comes into contact with the rotor in order of proximity as the preloaded force becomes larger.(b) The elastic deformation measured on the teeth near the rotor, is greater than it is away from the rotor.(c) The circumferential speeds of thye teeth are almost the same.(d) The squeal vibration with a frequency of 4.9 kHz is measured on the specific teeth.USM has two problems for constant speed drive, one is the influence of temperature rise during operation, and the other is the influence of initial deformations of the stator and the rotor. The adaptive control method has been applied to achieve constant speed drive, however, it is difficult to design a controller systematically.In this study H_* repetitive control method is applied as follows :(a) H_* speed control system is designed for robust stability against the influence of the temperature fluctuation.(b) A repetitive compensator is attached to improve the characteristic of disturbance rejection.The efficiency of the repetitive compensator is also confirmed by the control experiment.