Glossary
Technical terms, their standard sources, and repository terms still to review
Snapshot of this document in the GEMs repository. The repository itself is the current version. Bản chụp tài liệu này trong repo GEMs. Bản đang chạy nằm ở chính repo.
Technical terms in this repository follow standard usage in robotics, embedded systems and systems engineering. Where the repository once used a term of its own, this page says what the standard term is and whether the repository has changed over to it.
Standard terms as used here
| Term | Meaning here | Standard source |
|---|---|---|
| Main Controller | The operating intelligence: it decides, and holds the memory, the world model and the accumulated experience. It runs by DIL, wholly off the body, and is not specified in this repository (01) | This repository's term (Plone, 2026-11-05) |
| IPC | Industrial PC: the computer at the control station where the Main Controller runs | General usage |
| Unit | One GEMs body: a set of sensor and effector channels the Main Controller's host takes in, with an identity of its own (GEMs01, GEMs02). It runs by RSIL | This repository's term |
| Real-time Control Layer | The unit's tier for the whole-body loops the link is too slow to close — state estimation, balance, reflex, the safe-state supervisor. It executes setpoints; it does not decide | This repository's term, for a role, not a product |
| Real-time computer | The processor that carries the Real-time Control Layer; decision D-3 chooses a microcontroller under an RTOS or an embedded computer under a real-time Linux kernel | — |
| MCU | Microcontroller: here, the tier of per-device loops — joint current and position, battery management, secure element, beacon | General usage |
| DAQ | Data acquisition: sensor front-ends, capture and timestamping at source, feature extraction and compression; its computer is the edge AI module | General usage, widened here to include compression |
| OBC | On-board computer: the unit's kernel for a lagging or lost link. It stands by while the IPC is online and holds command only on a trigger (07.5) | General usage (spacecraft and vehicle on-board computers) |
| Firmware | Code running directly on a microcontroller, bare metal or under an RTOS — joint drive boards, the battery management board, the secure element, the beacon radio, and the real-time computer if D-3 makes it a microcontroller | ISO/IEC 12207: "a combination of a hardware device and computer instructions or computer data that reside as read-only software on the hardware device"; vocabulary per ISO/IEC/IEEE 24765 |
| Software | Code running under an operating system on an embedded computer — Linux, with or without a real-time kernel — device drivers included | General usage; drawing the line at the processor is this repository's application of the firmware definition above |
| Hard real-time | A task whose deadline miss is a failure and may cause harm; its worst case must be bounded by construction | Real-time systems literature (Kopetz; Buttazzo) |
| Firm real-time | A task whose late result has no value and is discarded, without harm | same |
| Soft real-time | A task whose late result has reduced value | same |
| Non-real-time | A task with no deadline | same |
| Deadline, deadline miss | The time by which a task must complete, and the event of it not doing so | same |
| RTOS | Real-time operating system: one whose scheduling bounds worst-case response | same |
| PREEMPT_RT | The real-time preemption patch set for the Linux kernel, which bounds scheduling latency closely enough for many real-time control loops; the bound is established by measurement | Reghenzani et al., "The Real-Time Linux Kernel: A Survey on PREEMPT_RT", ACM Computing Surveys |
SCHED_FIFO |
Linux fixed-priority real-time scheduling policy | Linux kernel documentation |
SCHED_DEADLINE |
Linux earliest-deadline-first scheduling with a constant bandwidth server; each task declares runtime, deadline and period, and deadlines hold only while total utilisation stays within the cores available | Linux kernel documentation |
| Reference model | An executable specification that a port is checked against; it runs on no target. Here: reference/ |
General usage ("golden model") |
| EBOM, MBOM, SBOM | Engineering, manufacturing and software bills of materials | see hardware/bom/ |
| TM, LAB | Commercially available; demonstrated in the laboratory but not scaled | 00 |
⟦IMPL⟧, ⟦CTRL⟧ |
Left open until parts are chosen; left to the operator | 09 |
Where each vocabulary belongs
Two vocabularies meet in this repository, and each has a place.
RSIL and DIL terms are kept, in the contract layer. They name concepts of the companion specifications, not components, and renaming them would break the correspondence with those papers. Their place is where the contract is stated and tested — spec 08, protocol/ — and the field names of the audit-log record schema, which carries the contract's evidence. Verified against the RSIL text: appraisal, scar, appraisal under a scar-dominated field, anchored context, emission, trace, agency (AgencyTag, SELF_CAUSED), caused-by-me, region, resistance, reflex, and the requirement labels INV-6, INV-8, C5, E1–E4.
Everywhere else, engineering terms. Where an engineering item realises a contract term, it takes the engineering name and cites the contract term once: "reflex decision (RSIL INV-8: appraisal under a scar-dominated field)".
Terms changed to standard usage
| Was | Now | Why |
|---|---|---|
| Firmware "owns time", software "owns meaning"; "anything with a deadline is firmware" | Firmware runs directly on a microcontroller, software under an operating system; hard, firm, soft and non-real-time by the consequence of a late result, held in realtime_config/; every hard real-time task runs on a platform whose worst-case latency is bounded — by construction on a microcontroller, by measurement under a real-time Linux policy |
The old rule merged two independent classifications. It made a camera driver on the application processor "firmware", and it placed agency tagging on both sides of the line at once. A first correction tied hard real-time to firmware; that still bound one axis to the other, and was relaxed to a rule on the platform |
| Emission log (the component) | Audit log; AuditLog in code |
Emission stays as the contract's word for an output event, and anchored as the name of the tier that holds its anchored context (Tier.ANCHORED, matching spec 06.4) |
| Low-power trace (the component), trace emitter, trace radio | Low-power beacon, beacon radio | Low-power trace stays as the name of RSIL C5, which the beacon satisfies |
| Floor power | Quiescent power | Also avoids a clash with RSIL's unrelated floor-tag |
| Vigilance circuit, vigilance rail | Always-on wake-up circuit, always-on rail | Not an RSIL term |
| On-body / off-body seat | On-board / off-board compute | "Seat" is not an RSIL term |
| "One intelligence, two seats" | The controller is off the body: the Main Controller on the IPC; each unit its sensors and effectors (spec 01) | The old principle put part of the intelligence on the body, where 07.5 said nothing decides (Plone, 2026-11-05) |
| Real-time controller | Real-time Control Layer for the tier; real-time computer for its processor | "Controller" now names only the Main Controller, off the body |
| Local core | OBC, the on-board computer | The kernel is a computer of its own, and holds command only on a trigger |
| Pre-closed appraisal | Reflex decision in engineering text; appraisal under a scar-dominated field (RSIL §9.7) in the contract | "Pre-closed" was this repository's paraphrase, not RSIL's wording |
| Appraisal, integration (reflex stages) | Reflex decision, state assembly | |
| Agency classification | Agency tagging, a firmware task | Agency itself is the contract's term and stays |
Decision recorded: what C5 asks of the body
RSIL defines C5 as "self-reports low power: the system emits a trace of the loop is running weakly", and states that C5 is not a criterion for detecting a dead loop. Spec 06.5 first met it with a beacon whose content was a liveness signal at low electrical power — closer to a heartbeat, which is what RSIL says C5 is not.
Resolved by the author, 2026-09-26: the beacon stays as the channel, and carries the loop's own report in a loop_state field, unaltered and with its age. The body transmits; the loop reports. The beacon's alive field is kept for the delegated watch during sleep and is explicitly not C5. Dead-loop detection is placed where RSIL places it — in a stored record outside the loop, here the audit log synchronised off-board. See 06.5, 08.1 and protocol C-10.