This work focuses on the agile transportation of liquids with robotic manipulators. In contrast to existing methods that are either computationally heavy, system/container specific or dependant on a singularity-prone pendulum model, we present a real-time slosh-free tracking technique. This method solely requires the reference trajectory and the robot's kinematic constraints to output kinematically feasible joint space commands. The crucial element underlying this approach consists on mimicking the end-effector's motion through a virtual quadrotor, which is inherently slosh-free and differentially flat, thereby allowing us to calculate a slosh-free reference orientation. Through the utilization of a cascaded proportional-derivative (PD) controller, this slosh-free reference is transformed into task space acceleration commands, which, following the resolution of a Quadratic Program (QP) based on Resolved Acceleration Control (RAC), are translated into a feasible joint configuration. The validity of the proposed approach is demonstrated by simulated and real-world experiments on a 7 DoF Franka Emika Panda robot. Code: https://github.com/jonarriza96/gsft Video: https://youtu.be/4kitqYVS9n8

翻译：本工作聚焦于机器人操作器对液体的敏捷运输。与现有方法（通常计算量大、受限于系统或容器、或依赖易出现奇异性的单摆模型）不同，我们提出了一种实时无晃荡跟踪技术。该方法仅需参考轨迹和机器人的运动学约束，即可输出运动学可行的关节空间指令。该方法的核心理念在于通过一个虚拟四旋翼飞行器模仿末端执行器的运动——该虚拟模型本质上具有无晃荡性和微分平坦性，从而允许我们计算无晃荡的参考姿态。通过级联比例-微分（PD）控制器，该无晃荡参考姿态被转换为任务空间加速度指令，进而通过基于解析加速度控制（RAC）的二次规划（QP）求解，转化为可行的关节配置。通过在七自由度Franka Emika Panda机器人上的仿真与实物实验，验证了所提方法的有效性。代码：https://github.com/jonarriza96/gsft 视频：https://youtu.be/4kitqYVS9n8