Projected Inverse Dynamics Control (PIDC) is commonly used in robots subject to contact, especially in quadrupedal systems. Many methods based on such dynamics have been developed for quadrupedal locomotion tasks, and only a few works studied simple interactions between the robot and environment, such as pressing an E-stop button. To facilitate the interaction requiring exact force control for safety, we propose a novel interaction force control scheme for underactuated quadrupedal systems relying on projection techniques and Quadratic Programming (QP). This algorithm allows the robot to apply a desired interaction force to the environment without using force sensors while satisfying physical constraints and inducing minimal base motion. Unlike previous projection-based methods, the QP design uses two selection matrices in its hierarchical structure, facilitating the decoupling between force and motion control. The proposed algorithm is verified with a quadrupedal robot in a high-fidelity simulator. Compared to the QP designs without the strategy of using two selection matrices and the PIDC method for contact force control, our method provided more accurate contact force tracking performance with minimal base movement, paving the way to approach the exact interaction force control for underactuated quadrupedal systems.

翻译：预测反向动态控制(PIDC)通常用于接触的机器人,特别是四级系统。基于这种动态的许多方法已经为四重移动任务开发出许多基于这种动态的方法,只有几部作品研究机器人与环境之间的简单互动,例如按E-stop按钮。为了便利需要精确武力控制的相互作用,我们提议了一个新型互动力量控制机制,用于使用投影技术和二次编程的未充分激活的四重系统。这一算法允许机器人在不使用强制传感器的同时对环境应用所需的互动力量,而不满足物理限制和引发最低限度的基础运动。与以往的投影方法不同,QP设计使用两个选择矩阵,在其等级结构中使用了两个选择矩阵,以便利武力和运动控制之间的脱钩。为了便利这种互动,拟议算法得到高纤维模拟器中四重机器人的验证。与QP设计相比,没有使用两个选择矩阵和PIDC的接触力控制方法,我们的方法提供了更精确的接触力跟踪功能,在最小基础互动方法下,为最小的基调方法铺平了基反方向。