Richard A Volz

US Patent:

54106850, Apr 25, 1995

Filed:

Jul 1, 1993

Appl. No.:

8/086224

Inventors:

Venu Prabhakar Banda - College Station TX
Richard A. Volz - College Station TX

Assignee:

Regents of the University of Michigan - Ann Arbor MI

International Classification:

G06F 945

US Classification:

395575

Abstract:

A non-intrusive method and system for recovering the state of a computer system including a memory having first and second matched levels. The first level is connected to a target processor and the second level is connected to a checkpoint processor which is also connected to the target processor. In an example of the invention, a two phase, non-intrusive method and system for debugging parallel computer programs is provided. The program has checkpoint instructions therein. In the first phase the execution of the program is monitored non-intrusively from a bus connecting the target processor to the first level of memory. A sequence of relevant program instructions is stored in an event table. Upon encountering a checkpoint instruction, the target processor cues the checkpoint processor to initiate a non-intrusive checkpointing strategy utilizing the two-level memory with an E-bit scheme. In the second phase the information collected during the first phase is utilized to replay an identical execution of the program, in a simulated environment.

US Patent:

50460226, Sep 3, 1991

Filed:

Mar 10, 1988

Appl. No.:

7/166337

Inventors:

Lynn A. Conway - Ann Arbor MI
Richard A. Volz - Saline MI
Michael W. Walker - Ann Arbor MI

Assignee:

The Regents of the University of Michigan - Ann Arbor MI

International Classification:

G06F 1500

US Classification:

364513

Abstract:

Systems and methods for performing tele-operations with the active assistance and supervision of a cognitive agent, such as a human being, who generates a future path plan in real time for immediate use by an automated on-line controlled agent, such as a work robot or other manipulator, are disclosed. The systems and methods may employ a visual display to present images of the controlled agent, of a foward simulation of the controlled agent, and of the future path plan being generated to enable a human operator to assess and control the on-going activity. The system simultaneously operates the controlled agent and produces the forward simulation and path plan, all under real time conditions. The cognitive agent, display and forward simulation equipment may be at one location and the controlled agent and its controller at another remote location. The forward simulation may be selectively operated in one of three modes: a time-and-position synchronized mode, a position-synchronized, time-desynchronized mode, and a mode where neither time nor position are synchronized with the controlled agent.