Contact motion planning including force direction with relaxing impact

In contrast to precise position control of the robot arms and manipulators, the force control has been studied recently. The robust position control does not allow the robots to share the same space with humans because the robots faithfully follow the position command, and it may lead to break the contacted environments. The impedance and compliance control could set impedances of robots so that the control laws have been utilized for interaction with environments or humans. By using these controls, the robots safety contact with the environments. However, following performance to the reaction force due to the collision generally depends on the setting impedance of the robots. When the robots contact with the hard objects or moving objects, the large force may occur. In order to cope with this, the information of the environment position implicitly is used, as the background that resent techniques of environmental recognition have been precise and high-speed. In the study, the method of impulsive force suppression considering contacted object position is proposed. The method does not use the switching of position control for approaching and force control after the contact. Moreover, the force control is accomplished in desired adding force direction without switching. Therefore, the method does not require especial orbit generation. The validity of the proposed method is confirmed through the simulations and experiments.