Parameter Design Aimed at Improving the Practicality of the Multiple Virtual Dynamics-based Force Control

Contact task execution in unknown environments is fundamental to robotic applications, requiring three essential functions: accurate position tracking, safe contact establishment, and achievement of desired contact force. In our previous work, the Multiple Virtual Dynamics-based Force Control (MVDFC) was proposed. This method seamlessly integrates these three functions; however, several challenges remain when considering practical force control. The first challenge is that time delays in the force sensor can destabilize the control system. The second challenge is that loss of contact with the environment during a force control task can result in acceleration of robot and collisions with the environment. These two challenges are commonly encountered in various force control methods. Here, a key feature of MVDFC is its flexibility, allowing the motion of virtual objects in each virtual dynamics to be independently designed. Therefore, by leveraging this flexibility, it is possible to overcome the two challenges without compromising the three functions. This study proposes a direction for parameter design to address the above issues, and its effectiveness is demonstrated through both simulations and experiments.