Kyo Kutsuzawa

Acceleration Control for Dynamic Manipulation of a Robot Turning Over Objects

This study deals with dynamic object manipulation by a robot using a tool. In order to keep the contact between the held spatula and the manipulated object, a variety of movements satisfying conditions in acceleration dimension should be planned. However, it is quite difficult to assure the acceleration to stay in a certain range in case disturbances exist. Therefore, this study proposes a control architecture for acceleration control and discusses how to develop a controller suitable for dynamic object manipulation. Comparison through simulation and experimental results reveals the features of the proposed control system.

Estimation of individual force at three contact points on an end-effector by a six-axis force/torque sensor

When robots interact with the environment, it is necessary for them to detect and control contact forces. In many cases, force/torque sensors or tactile sensors on robots do not contact the environment directly, but instead contact through end-effectors or grasped objects. Thus, robots have to estimate actual contact forces through insensitive objects. However, estimating multiple contact forces through insensitive objects is an ill-posed problem. This paper proposes a method of estimating contact forces on three points separately with a six-axis force/torque sensor on an end-effector. We discovered that the components of contact forces normal to the plane defined by the three contact points can be found uniquely by applying static equilibrium of force and moment. The tangential components of contact forces can also be determined by the use of an additional algorithm. The validity of the proposed method is confirmed by experimental results.