Designing a virtual whole body tactile sensor suit for a simulated humanoid robot using inverse dynamics

Abstract

Abstract-In this paper, we propose a novel architecture to estimate external forces applied to a compliantly controlled balancing robot in simulations. We use similar dynamics equations used in the controller to find mismatches in the available sensory data and associate them to an unknown external force. Then by decomposing Jacobians, we search over the surface of all body links in the robot to find the force application point. By approximating link geometries with ellipsoids, we can derive analytic solutions to solve the search problem very fast in real time. The proposed approach is tested on a complex humanoid robot in simulations where it outperforms static estimators over fast dynamic motions. We foresee a lot of applications for this method especially in human-robot interactions where it can serve as a whole body virtual suit of tactile sensors. It can also be very useful in identifying the inertial properties of objects being manipulated or mounted on the robot like a backpack.

Modeling and Control of Multi-Arm and Multi-Leg Robots: Compensating for Object Dynamics During Grasping

“…Recently, we did a first step in this direction, however for a very simple scenario [34]. Methods which estimate external wrenches and their application locations on-line may also detect contacts [35], [36].…”

A Model-Based Hierarchical Controller for Legged Systems Subject to External Disturbances

“…For the robot to be robust to external disturbance it needs to estimate how much external forces are applied. Previous work estimates the external force based on sensor fusion [11] [12]. However, the force/torque sensor data is usually unreliable.…”

Experimental Study for Controller-Friendly Contact Estimation for Humanoid Robot

“…These non-desired contacts must be detected and to be handled by the planner or the controller. Several methods have been proposed to detect contacts, as seen in recent research [8], [9], [10], [11], [12]. There are also some works about the physical interaction between a humanoid and a human [13], [14], [15], [16].…”

“…This is also the reason why other methods of contact detection are not considered or compared in this paper. As in [8], [10], [11], the contact estimation on (humanoid) robots is usually achieved by three steps: (1) contact detection, (2) contact force estimation, and (3) contact point localization. Since a humanoid has a floating base, the robot is always in contact with the environment.…”