Revise a controller while retaining its failure

Retain the failure before proposing a fix

Select standard hardware’s delayed scenario at gain 6 W/K. The lab fixes hardware and zero correction; you can change gain and the public operating scenario. Before trying a new setting, write what failed and what you expect a change to do. Save the original capture and add a note identifying the relevant tail samples. This workflow records development evidence; it is not the future cumulative project’s immutable candidate-freezing workflow.

The gain-6 delayed tail at 90, 100, 110 and 120 seconds is approximately 31.474386, 31.295085, 30.593203 and 29.694914°C. The first two samples exceed 31°C even though the final value is inside the band. Peak, energy and token criteria still pass. Your proposed mechanism should explain that particular failure: old sensor information keeps the heater command high after the true temperature has risen.

Predeclare a bounded revision

Propose lowering gain from 6 to 2 W/K while keeping the delayed scenario unchanged. Predict whether weaker response to an outdated error will reduce overshoot. Also predict a possible cost: reduced response strength could leave nominal tracking farther from target. Record both predictions before inspecting the revised output, then save the revised recipe and comparison note.

The current lesson prediction and reflection fields are learner-authored working records. Do not claim they create a secure hidden test or an immutable submitted design. All twelve case definitions and worked results are public, and a changed public scenario may already be familiar. Disclose that familiarity rather than erasing earlier captures to manufacture a fresh-looking sequence.

Compare all requirements on matched runs

The revised delayed gain-2 tail is approximately 30.341073, 30.359363, 30.293904 and 30.201020°C. Each value lies in the supplied inclusive 29–31°C band. Its peak is about 30.359363°C, input energy 1,922.517416 J, and cost remains three tokens. It passes all displayed requirements in this scenario.

The failed gain-6 delayed run used 1,905.207928 J, so the successful revision uses about 17.309488 J more, not less. The redesign improved the failed temperature criterion while slightly worsening input energy, still within its allowance. Preserve that tradeoff; do not describe the new setting as uniformly superior.

Now inspect the already public nominal comparison. Gain 2 ends near 29.766220°C and gain 6 near 29.998648°C. Both meet the nominal criteria, but the lower gain has a larger final error. A choice can be justified by robust performance over the stated conditions without pretending to optimize every indicator. Specify whether your priority is closer nominal tracking, delay tolerance, energy use or another supplied requirement.

Test whether the explanation addresses other failures

Changing gain does not remove the +2°C sensor offset. All three allowed gains fail that scenario’s lower tail limit. Nor can gain overcome the 8 W capacity limit: all three limited runs end near 25.590446°C. Use these counterexamples to bound the redesign claim. “Gain 2 resolves the supplied delayed-case tail failure” is supported; “gain 2 fixes the device” is too broad.

A useful failure log includes condition, violated requirement, retained receipt, proposed mechanism, change, retest result and unresolved alternative. NASA’s product-realization guidance connects verification evidence with stated requirements and distinguishes it from validation of intended use. This synthetic exercise neither demonstrates a physical prototype nor certifies operation across real environments.

Transfer: review a partial comparison

A colleague compares the original full 120-second delayed gain-6 energy with a revised gain-2 run stopped at 90 seconds. The revised energy is lower at that earlier endpoint, and its 90-second temperature is inside the band. Can the colleague conclude that the revision uses less energy and passes the original requirement? Identify what evidence is missing.

Check the unequal-duration transfer

No. The durations are unequal, so the energy totals answer different service questions. The original tail requirement also includes 100, 110 and 120 seconds, which the shortened comparison omits. Retain a full 120-second revised run, compare every specified tail sample and total energy, and report the actual tradeoff. A passing 90-second observation alone is insufficient.

For genuinely unfamiliar transfer, a human must supply a new, adequately specified failure or evidence packet and review the learner’s reasoning with help and exposure disclosed. Tuning after seeing that assignment makes subsequent comparisons developmental. The current captures remain useful public practice, not authenticated mastery. Return to prototype evidence to organize the argument or revisit sensor delay to strengthen its mechanism.