Using a 3DOF Parallel Robot and a Spherical Bat to hit a Ping-Pong Ball

Playing the game of Ping-Pong is a challenge to human abilities since it requires developing skills, such as fast reaction capabilities, precision of movement and high speed mental responses. These processes include the utilization of seven DOF of the human arm, and translational movements through the legs, torso, and other extremities of the body, which are used for developing different game strategies or simply imposing movements that affect the ball such as spinning movements. Computationally, Ping-Pong requires a huge quantity of joints and visual information to be processed and analysed, something which really represents a challenge for a robot. In addition, in order for a robot to develop the task mechanically, it requires a large and dexterous workspace, and good dynamic capacities. Although there are commercial robots that are able to play Ping-Pong, the game is still an open task, where there are problems to be solved and simplified. All robotic Ping-Pong players cited in the bibliography used at least four DOF to hit the ball. In this paper, a spherical bat mounted on a 3-DOF parallel robot is proposed. The spherical bat is used to drive the trajectory of a Ping-Pong ball.Fil: Trasloheros, Alberto. Universidad Aeronáutica de Querétaro; MéxicoFil: Sebastián, José María. Universidad Politécnica de Madrid; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Torrijos, Jesús. Consejo Superior de Investigaciones Científicas; España. Universidad Politécnica de Madrid; EspañaFil: Carelli Albarracin, Ricardo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Automática. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Automática; ArgentinaFil: Roberti, Flavio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Automática. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Automática; Argentin

Reactive Motions In A Fully Autonomous CRS Catalyst 5 Robotic Arm Based On RGBD Data

This study proposes a method to perform velocity estimation using motion blur in a single image frame along x and y axes in the camera coordinate system and intercept a moving object with a robotic arm. It will be shown that velocity estimation in a single image frame improves the system\u27s performance. The majority of previous studies in this area require at least two image frames to measure the target\u27s velocity. In addition, they mostly employ specialized equipments which are able to generate high torques and accelerations. The setup consists of a 5 degree of freedom robotic arm and a Kinect camera. The RGBD (Red, Green, Blue and Depth) camera provides the RGB and depth information which are used to detect the position of the target. As the object is moving within a single image frame, the image contains motion blur. To recognize and differentiate the object from blurred area, the image intensity profiles are studied. Accordingly, the method determines the blur parameters based on the changes in the intensity profile. The aforementioned blur parameters are the length of the object and the length of the partial blur. Based on motion blur, the velocities along x and y camera coordinate axes are estimated. However, as the depth frame cannot record motion blur, the velocity along axis in the camera coordinate frame is initially unknown. The vectors of position and velocity are transformed into world coordinate frame and subsequently, the prospective position of the object, after a predefined time interval, is predicted. In order to intercept, the end-effector of the robotic arm must reach this predicted position within the time interval as well. For the end-effector to reach the predicted position within the predefined time interval, the robot\u27s joint angles and accelerations are determined through inverse kinematic methods. Then the robotic arm starts its motion. Once the second depth frame is obtained, the object\u27s velocity along z axis can be calculated as well. Accordingly, the predicted position of the object is recalculated, and the motion of the manipulator is modified. The proposed method is compared with existing methods which need at least two image frames to estimate the velocity of the target. It is shown that under identical kinematic conditions, the functionality of the system is improved by times for our setup. In addition, the experiment is repeated for times and the velocity data is recorded. According to the experimental results, there are two major limitations in our system and setup. The system cannot determine the velocity along z in the camera coordinate system from the initial image frame. Consequently, if the object travels faster along this axis, it becomes more susceptible to failure. In addition, our manipulator is an unspecialized equipment which is not designed for producing high torques and accelerations. Accordingly, the task becomes more challenging. The main cause of error in the experiments was operator\u27s. It is necessary to have the object pass through the working volume of the robot. Besides, the object must be still inside the working volume after the predefined time interval. It is possible that the operator throw the object within the designated working volume, but it leaves it earlier than the specified time interval

Robotic Contact Juggling

We define "robotic contact juggling" to be the purposeful control of the motion of a three-dimensional smooth object as it rolls freely on a motion-controlled robot manipulator, or "hand." While specific examples of robotic contact juggling have been studied before, in this paper we provide the first general formulation and solution method for the case of an arbitrary smooth object in single-point rolling contact on an arbitrary smooth hand. Our formulation splits the problem into four subproblems: (1) deriving the second-order rolling kinematics; (2) deriving the three-dimensional rolling dynamics; (3) planning rolling motions that satisfy the rolling dynamics; and (4) feedback stabilization of planned rolling trajectories. The theoretical results are demonstrated in simulation and experiment using feedback from a high-speed vision system.Comment: 16 pages, 14 figures. | Supplemental Video: https://youtu.be/QT55_Q1ePfg | Code: https://github.com/zackwoodruff/rolling_dynamic

DribbleBot: Dynamic Legged Manipulation in the Wild

DribbleBot (Dexterous Ball Manipulation with a Legged Robot) is a legged robotic system that can dribble a soccer ball under the same real-world conditions as humans (i.e., in-the-wild). We adopt the paradigm of training policies in simulation using reinforcement learning and transferring them into the real world. We overcome critical challenges of accounting for variable ball motion dynamics on different terrains and perceiving the ball using body-mounted cameras under the constraints of onboard computing. Our results provide evidence that current quadruped platforms are well-suited for studying dynamic whole-body control problems involving simultaneous locomotion and manipulation directly from sensory observations.Comment: To appear at the IEEE Conference on Robotics and Automation (ICRA), 2023. Video is available at https://gmargo11.github.io/dribblebot

Vision-Based Control of the Robotenis System

In this paper a visual servoing architecture based on a parallel robot for the tracking of faster moving objects with unknown trajectories is proposed. The control strategy is based on the prediction of the future position and velocity of the moving object. The synthesis of the predictive control law is based on the compensation of the delay introduced by the vision system. Demonstrating by experiments, the high-speed parallel robot system has good performance in the implementation of visual control strategies with high temporary requirement

Nonprehensile Dynamic Manipulation: A Survey

Nonprehensile dynamic manipulation can be reason- ably considered as the most complex manipulation task. It might be argued that such a task is still rather far from being fully solved and applied in robotics. This survey tries to collect the results reached so far by the research community about planning and control in the nonprehensile dynamic manipulation domain. A discussion about current open issues is addressed as well