Force Perception of Industrial Robot Based on Multiparameter Coupled Model The precision force sensing information of industrial robots to the environment is important for highprecision and flexible assembly operations. This paper proposed a calibration and calculation method to the contact force with the data from a sixdimensional forcetorque sensor, which is installed between the end of the robot and the endeffector. In the proposed method, a multiparameter coupled model was considered including the gravity of the endeffector, the zeropoint of the sensor and the installation angle of sixdimensional forcetorque sensor. The contact forcetorque could be precisely obtained using this model, and the influence of the gravity and zero drift of sensor can be compensated. Experiments were performed with KUKA iiwa. The results show that the forcetorque information was more precise with the coupled model.

Nonlinear Disturbance Observer for External Force Estimation in a Cooperative Robot In humanrobot cooperation, where the robot shares workspace with humans, safety of the operator becomes a major concern. To this aim, the robot is required to detect forces from the human operator and the environment, and react to them accordingly. Since force sensors can be very expensive, force estimation methods are proposed. In this paper, the goal is to estimate the external forces acting on the endeffector of the robot. These forces make torques at the joint space. To estimate the applied joint space external torques, a nonlinear disturbance observer is proposed. The estimated torque can be converted into task space force, using the Jacobian matrix. The suggested method is demonstrated on a WallMoBot, which is designed to help the operator to install heavy glass panels. Simulation results and preliminary experimental results are presented to show the validity of the proposed observer in estimating the applied joint space external torques of the WallMoBot.