OMVA Draft 0.1 · Request for Comment

Concept Principles Interfaces Spec Family Get Involved

Open Modular Vehicle Architecture

A car built to be repaired, not replaced.

Right now, a modern car is a closed, proprietary system — when a module fails, you're locked into one manufacturer's parts, one manufacturer's price, and one manufacturer's timeline. OMVA proposes an open interface standard for the automobile: the mechanical, electrical, and data sockets a vehicle plugs into, so independent engineers, small manufacturers, and universities can build compatible modules the way independent companies build USB or PCIe devices — without asking permission from a single company that controls the whole car.

Read the Draft 0.1 spec → Contribute your expertise

$OMVA modular hybrid platform concept render — exploded chassis view showing slide-in power cassette, underfloor battery drawer, HVAC and electrical control cassettes, and quick-swap corner modules, with robotic service arms performing automated installation$

Concept render — illustrative only. No dimension, connector, or timing value shown here is a validated engineering specification.

What this is

A proposed open standard for automobile interfaces — mechanical, electrical, data, and diagnostic — so major subsystems can be designed, built, diagnosed, and replaced independently of any single vehicle maker. The goal isn't to design a car. It's to design the sockets a car plugs into.

What this isn't

Not a certified safety standard — nothing here has been validated by qualified engineering analysis, physical testing, or a regulatory body. Not a finished product or a company. It's a published concept framework, released for engineers, researchers, universities, and the right-to-repair community to critique, fork, and build on.

OMVA-000

Core principles

Standardize interfaces, not implementations

Define mounting datums, envelopes, electrical interfaces, and diagnostics — without dictating how any manufacturer builds the part inside.

Repair by substitution

A failed module comes out, a known-good one goes in. The failed unit gets diagnosed and rebuilt on a bench, not in the vehicle.

Manual-operable baseline

Every interface must be serviceable with hand tools by an independent technician. Robotic swap infrastructure is an accelerant, never a requirement.

Long-life platform

The chassis and structural safety cell are built for decades of service. Shorter-life subsystems are what's replaceable.

Condition-aware operation

The vehicle continuously monitors vibration, temperature, and electrical signatures to estimate remaining useful life before failure.

Safety remains deterministic

AI can predict and diagnose. It is never the final authority on a safety-critical value — that's validated engineering, full stop.

OMVA-100 — Mechanical Interface Architecture

Self-aligning by design, not by luck

Every module interface aligns mechanically before any electrical or fluid connection is permitted to engage, using a round-pin-plus-diamond-pin locating scheme borrowed from precision fixture design — the same discipline used for decades in injection-mold tooling — so the interface constrains all six degrees of freedom without the two locators fighting each other.

01

Support → capture → align → seat → lock → connect → verify — the module's weight is always carried by rails or a robot, never by the alignment pins.

02

Hardened, replaceable locator cartridges — not a bushing pressed into the chassis — absorb wear and isolate against galvanic corrosion on an aluminum structure.

03

The same sequence, same locators, same lock — for a technician with hand tools or a robot arm. Neither gets a privileged interface.

Power & energy — separate interfaces

A hybrid needs a conversion device and a storage device at once — they aren't alternatives, they're two sockets, differently populated per configuration.

ICE

Engine only

HYBRID

Engine + small battery

PHEV

Engine + medium battery

BEV

Drive unit + large battery

Real-world precedent

NIO's Power Swap Station 4.0 completes an automated battery swap in 144 seconds, and the network passed 100 million cumulative swaps in February 2026 — strong proof that fast, automated physical module exchange works at production scale. What doesn't yet exist anywhere is the open, publicly governed version — any manufacturer building to a published interface, not a bilateral deal with one company. That's the gap OMVA proposes to fill.

Specification family

Where the standard stands today

Four documents are drafted. Everything else is a placeholder waiting for someone with the right domain expertise to take it on.

OMVA-000 Philosophy, scope, liability posture, and the specification family Drafted

OMVA-100 Mechanical interface architecture — self-aligning guide system, docking sequence Drafted

OMVA-160 / 700 Structural safety cell, replaceable exterior shell, materials circularity Drafted

OMVA-110–150 Power, energy storage, transmission, thermal, corner, and steering interfaces Placeholder

OMVA-200–250 Electrical architecture, comms network, module discovery, diagnostic and software APIs Placeholder

OMVA-400 / 500 Safety architecture, cybersecurity, functional safety, serviceability requirements Placeholder

OMVA-600–690 Vehicle health architecture — baseline fingerprinting, anomaly detection, remaining useful life, fleet learning Placeholder

Prior art, told straight

This has been tried before. Here's what happened.

OSVehicle's Tabby (2013)

A genuinely open chassis, CC BY-SA licensed, 2- or 4-seat, swappable ICE, hybrid, or electric drivetrain. Then it got rebranded to Open Motors and turned into a $12,000–$17,500 single-vendor product for funded startups. No open CAD release since 2015. It didn't fail technically — it got bought and shelved, and nothing has happened with open modular vehicles since, precisely because of that.

Why now is different

In 2013 you needed a real engineering team to design a compliant part from open blueprints. With published mechanical, electrical, and data interfaces acting like an API, AI-assisted design tools let an individual engineer or a small shop design and validate a new module against the spec — no automaker's R&D budget required. That shift, not any single technical choice, is what makes trying this again worth it.

OMVA-004 — Governance

Structurally open, not just intentionally open

"We intend to stay open" wasn't a defense against what happened to Tabby. This is: any manufacturer, large or small, can build modules to the open interface — that's a feature, not a risk. What has to be structurally impossible is any single entity coming to own the standard itself.

Foundation, not a company

Modeled on the Linux Foundation. A nonprofit charter can't be acquired, sold, or folded into a product line the way a company can.

Copyleft with teeth

CERN-OHL-S requires anything built on OMVA's designs to stay open — a derivative can't be closed off and resold.

Certification mark

Anyone can build to the spec. Only conformance-tested implementations can call themselves OMVA-Certified.

Honest about the hard part

Why doesn't this already exist?

Liability

A vehicle maker is strictly liable for the vehicle as a system. There's no established legal framework yet for "the third-party module met OMVA spec" as a defense.

Crash structure

Mounting points aren't just brackets — they're tuned crash load paths. A swappable interface has to transfer those loads reliably across suppliers who never coordinate directly.

Business incentive

Proprietary parts and service are revenue automakers have no reason to give up voluntarily. This has to come from outside the incumbent industry.

Get involved

This needs to survive contact with people who know where it's wrong.

If you're a mechanical, electrical, or automotive-cybersecurity engineer — or a materials, regulatory, or functional-safety specialist — your critique of one section is worth more right now than new material. If you're a student or a lab looking for a thesis-scale open-hardware project, several of the placeholder specifications above are exactly that scale.

View the repo on GitHub → omva@rockyhardie.com

OMVA — Open Modular Vehicle Architecture · Draft 0.1 Concept initiated by Rocky Hardie, AI-assisted drafting