Position Tracking Control of a Miniature Water Hydraulic Rotary Actuator
Bibliographic record
Abstract
Over the past 20 years, research in the field of miniature actuators has increased substantially due to advances in smart material fabrication, semiconductor chip technology, and computer processing capability. Hydraulic cylinders offer many potential benefits as miniature actuators, including high power-to-weight ratio, mechanical stiffness, smooth motion, and the potential for high positional accuracy. Despite their benefits, the control of hydraulic cylinders with bore diameters under 10 mm has not been previously studied. The most significant obstacle to implementing the use of miniature cylinders is the unavailability of off-the-shelf proportional valves that are compatible with hydraulic fluid and precise enough for the position control task. In this paper, two novel model-based nonlinear control strategies are presented for the position control of a rotary actuator powered by two 4 mm bore diameter cylinders. Four off-the-shelf, low cost, 2/2 on/off miniature solenoid valves were used to control the flow of water to and from the cylinder chambers. A novel valve coordination scheme is also presented that allows the on/off valves to approximate the behavior of a proportional valve. The tracking performance of each controller was experimentally tested and both controllers were found to achieve steady-state positioning accuracies of the cylinders within ±0.07 mm. The robustness of the controllers to changes in payload mass and vertical orientation was also tested. Results from several experiments are presented and compared.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".