Trinkle, Jeff
Efficient State Estimation with Constrained Rao-Blackwellized Particle Filter
Li, Shuai, Lyu, Siwei, Trinkle, Jeff
Due to the limitations of the robotic sensors, during a robotic manipulation task, the acquisition of the object's state can be unreliable and noisy. Combining an accurate model of multi-body dynamic system with Bayesian filtering methods has been shown to be able to filter out noise from the object's observed states. However, efficiency of these filtering methods suffers from samples that violate the physical constraints, e.g., no penetration constraint. In this paper, we propose a Rao-Blackwellized Particle Filter (RBPF) that samples the contact states and updates the object's poses using Kalman filters. This RBPF also enforces the physical constraints on the samples by solving a quadratic programming problem. By comparing our method with methods that does not consider physical constraints, we show that our proposed RBPF is not only able to estimate the object's states, e.g., poses, more accurately but also able to infer unobserved states, e.g., velocities, with higher precision.
Toward Fine Contact Interactions: Learning to Control Normal Contact Force with Limited Information
Cui, Jinda, Xu, Jiawei, Saldaña, David, Trinkle, Jeff
Dexterous manipulation of objects through fine control of physical contacts is essential for many important tasks of daily living. A fundamental ability underlying fine contact control is compliant control, \textit{i.e.}, controlling the contact forces while moving. For robots, the most widely explored approaches heavily depend on models of manipulated objects and expensive sensors to gather contact location and force information needed for real-time control. The models are difficult to obtain, and the sensors are costly, hindering personal robots' adoption in our homes and businesses. This study performs model-free reinforcement learning of a normal contact force controller on a robotic manipulation system built with a low-cost, information-poor tactile sensor. Despite the limited sensing capability, our force controller can be combined with a motion controller to enable fine contact interactions during object manipulation. Promising results are demonstrated in non-prehensile, dexterous manipulation experiments.
Robotics: Science and Systems
Trinkle, Jeff (Rensselaer Polytechnic Institute) | Matsuoka, Yoky (University of Washington)
The conference Robotics: Science and Systems was held at the University of Washington in Seattle, from June 28 to July 1, 2009. More than 300 international researchers attended this single‐track conference to learn about the most exciting robotics research and most advanced robotic systems. The program committee selected 39 papers out of 154 submissions. The program also included invited talks. The plenary presentations were complemented by workshops.
Robotics: Science and Systems IV
Brock, Oliver (University of Massachusetts) | Trinkle, Jeff (Rensselaer Polytechnic Institute) | Ramos, Fabio (Australian Centre for Field Robotics)
Funding for the conference was provided by the National Science Foundation, the Naval Research Laboratory, ABB, Microsoft Research, Microsoft Robotics, Evolution Robotics, Willow Garage, and Intel. Springer sponsored the best student paper award. The meeting brought together more than 280 researchers from Europe, Asia, North America, and Australia. He showed how molecular motors exploit for the technical program. Twenty of the accepted thermal noise to achieve energy efficiency and papers were presented orally; the remaining 20 talked about the implications for building artificial were presented as posters.