A virtual vibration absorber (VVA) is a control algorithm that mimics the dynamics of a tuned mass damper, which can compensate for a harmonic disturbance of a specific frequency. A VVA may also be devised to compel the system to track a sinusoidal signal asymptotically. A novel sensorless contact-force detector is proposed for a four-bar-linkage manipulator utilizing two sets of VVA. One VVA acts as a harmonic-motion generator; another VVA compensates for the second harmonic distortion due to impact from the environment. Since the compensating VVA has a natural frequency completely matching that of the harmonic distortion, it makes a very sensitive force detector. Both numerical simulation and experimentation on a physical device are conducted to illustrate and verify the performance of the proposed method.

虚拟减振器 (VVA) 是一种模拟调谐质量阻尼器动力学的控制算法，可以补偿特定频率的谐波干扰。还可以设计 VVA 来强制系统渐近地跟踪正弦信号。为使用两组 VVA 的四杆连杆机械手提出了一种新型无传感器接触力检测器。一个 VVA 作为谐波运动发生器；另一个 VVA 补偿由于环境影响而产生的二次谐波失真。由于补偿 VVA 具有与谐波失真完全匹配的固有频率，因此它是一种非常灵敏的力检测器。在物理设备上进行了数值模拟和实验，以说明和验证所提出方法的性能。