YAML schema for Chrono::Vehicle model specification

A Chrono::Vehicle YAML FSI problem specification file defines the vehicle models and consists of two main objects:

• [required] The Chrono version (chrono-version) that is compatible with the YAML model specification. This is a string of the form M.m (major.minor) or M.m.p (major-minor-patch), although only the two fileds are verified for compatibility.
• [required] The model object which defines JSON specification files for the vehicle sub-systems.

Model specification

YAML schema

The YAML vehicle model specification file must follow the data/yaml/schema/vehicle_model.schema.yaml provided in the Chrono data directory:

# =============================================================================
# PROJECT CHRONO - http://projectchrono.org
#
# Copyright (c) 2025 projectchrono.org
# All rights reserved.
#
# Use of this source code is governed by a BSD-style license that can be found
# in the LICENSE file at the top level of the distribution and at
# http://projectchrono.org/license-chrono.txt.
# =============================================================================
#
# Schema for a YAML Chrono::Vehicle model specification file.
# The `chrono-version` must match the Chrono major and minor version numbers.
#
# =============================================================================
 
required: [chrono-version, model]
 
chrono-version:
  type: string
  description: Chrono version compatible with this YAML problem specification (M.m or M.m.p)
 
# -----------------------------------------------------------------------------
# Definitions of common Chrono types
 
vector3d: &VECTOR3D   # Specification of a ChVector3d
    type: array
    items:
        type: number
    minItems: 3
    maxItems: 3
 
# -----------------------------------------------------------------------------
# Definition of the vehicle model
 
model:
  description: |
    Schema for FSDI problem parameters.
    This schema defines the multibody and fluid models, the simulation parameters for the two solvers, and the co-simulation metastep.
  type: object
  required: [vehicle_json, engine_json, transmission_json]
  properties:
    vehicle_json:
      description: JSON file for vehicle model specification.
      type: string
    engine_json:
      description: JSON file for engine model specification.
      type: string
    transmission_json:
      description: JSON file for transmission model specification.
      type: string
    time_json:
      description: JSON file for tire model specification (WHEELED vehicles only).
      type: string
 
terrain_json:
  description: JSON file for rigid terrain specification.
  type: string
  default: ""
      
initial_position:
  <<: *VECTOR3D
  description: Initial vehicle position
  default: [0, 0, 0]
 
initial_yaw:
  description: Initial vehicle yaw
  type: number
  default: 0.0
 
chase_camera:
  description: PArameters for the vehicle chase camera.
  type: object
  required: [chassis_point, chase_distance, chase_height]
  properties:
    chassis_point:
      <<: *VECTOR3D
      description: Chase camera target point on chassis.
    chase_distance:
      description: Initial value of the horizontal distance between camera and target point
      type: number
    chase_height:
      description: Initial value of the vertical distance between camera and target point
      type: number