Contact Sensing: A Sequential Decision Approach to Sensing Manipulation Contact

This paper describes a new statistical, model-based approach to building a contact state observer. The observer uses measurements of the contact force and position, and prior information about the task encoded in a graph, to determine the current location of the robot in the task configuration space. Each node represents what the measurements will look like in a small region of configuration space by storing a predictive, statistical, measurement model. This approach assumes that the measurements are statistically block independent conditioned on knowledge of the model, which is a fairly good model of the actual process. Arcs in the graph represent possible transitions between models. Beam Viterbi search is used to match measurement history against possible paths through the model graph in order to estimate the most likely path for the robot. The resulting approach provides a new decision process that can be use as an observer for event driven manipulation programming. The decision procedure is significantly more robust than simple threshold decisions because the measurement history is used to make decisions. The approach can be used to enhance the capabilities of autonomous assembly machines and in quality control applications

Contact sensing--a sequential decision approach to sensing manipulation contact features

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1995.Includes bibliographical references (p. 179-186).by Brian Scott Eberman.Ph.D

Whole-Arm Manipulation: Kinematics and Control

This thesis explores the kinematics and control issues associated with an approach to manipulation that employs all of the available surfaces of a robot to interact with the workspace. This thesis explores manipulations of this type which we term whole-arm manipulation (WAM). A classification of WAM tasks into pushing, searching, enclosure, and exclusion is presented and examples of each are given. A technique for describing the task kinematics and compliance in terms of compliant line motions is presented. Compliance control requirements are discussed in light of these task requirements. Implementation of the kinematic solutions and control for whole-arm tasks is described for the MIT-WAM robot. The inverse kinematic problem of placing the last link of the robot along a desired line is derived and the resulting transformations are applied to a maximum path deviation algorithm to plan manipulator motions. The endtip cartesian kinematics is derived and applied to the problem of sensin..