Resolving Velocity-Degenerate Configurations (Singularities) of Redundant Manipulators
Bibliographic record
Abstract
Abstract A kinematically-(joint)-redundant spatial manipulator will not be velocity degenerate (singular) if any combination of six of its joints span the 6-system of general velocity. Therefore, all 6x6 sub-matrices of the matrix of joint screw coordinates J (commonly referred to as the Jacobian) must be rank deficient for a spatial joint-redundant manipulator to be velocity degenerate. Concurrency of zero 6x6 sub-matrix determinants of J allows sets of joint-displacement conditions leading to velocity-degenerate configurations to be identified. For actual manipulators, each set of degeneracy conditions must be checked to see if the conditions are feasible for existing device dimensions and occur within existing joint displacement limits. Within this work, the concept of concurrency of zero 6x6-sub-matrix determinants of J is considered and applied to the identification of velocity degeneracies for the Canadian Space Agency (CSA)/International Submarine Engineering (ISE) STEAR Testbed Manipulator (STM). The STM consists of two 7-jointed arms that are kinematically similar to the arms of the Special Purpose Dextrous Manipulator (SPDM) proposed for use on the International Space Station (ISS). Five unique 2-condition families of velocity degenerate configurations are found to cause velocity degeneracies for each of the 7-jointed arms. It is shown that only four of these five potential degeneracies correspond to reachable families of joint-displacement configurations for the CSA/ISE STM arms.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".