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RoadSurfaceTemperature
Full qualified VSS Path: Vehicle.Exterior.RoadSurfaceTemperature
Description: Temperature of the road surface beneath or ahead of the vehicle.
Comment: Distinct from Vehicle.Exterior.AirTemperature: the road surface can sit several degrees below the air, most notably on bridge decks and in shaded cuttings, so surface temperature is the determining input for icing risk when the air reads above freezing while the road is still frozen. A natural fusion input to Vehicle.Exterior.RoadSurfaceCondition alongside air temperature and Vehicle.ADAS.ESC.RoadFriction.MostProbable, and to Vehicle.Safety.RoadIcingState where available. Measurement method is implementation specific (typically infrared pyrometer) and the value may also originate from external road-weather infrastructure. Related to VSS issue #877 (Connected Safety signals).
flowchart LR Vehicle-->Exterior Exterior-->RoadSurfaceTemperature

Eclipse Leda: Usage Example

In Eclipse Kuksa.VAL Databroker CLI:

$ databroker-cli
sdv.databroker.v1 > connect
[connect] OK
sdv.databroker.v1 > get Vehicle.Exterior.RoadSurfaceTemperature
[get]  OK
Vehicle.Exterior.RoadSurfaceTemperature: ( NotAvailable )
sdv.databroker.v1 > set Vehicle.Exterior.RoadSurfaceTemperature 0
[set]  OK

Digital Auto: Playground

playground.digital.auto provides an in-browser, rapid prototyping environment utilizing the COVESA APIs for connected vehicles.

Vehicle Model Direct link to Vehicle Signal
ACME Car (EV) v0.1 Vehicle.Exterior.RoadSurfaceTemperature

Data Type & Unit
Path Vehicle.Exterior.RoadSurfaceTemperature VSS: Addressing nodes
Data type float VSS: Datatypes
Unit Celsius VSS: Units

Note: The float datatype is a floating point number which technically allows values between -3.4e ^ -38 and 3.4e ^ 38

Signal Information

The vehicle signal Vehicle.Exterior.RoadSurfaceTemperature is a Sensor.

The vehicle signal Vehicle.Exterior.RoadSurfaceTemperature is a Signal.

Feedback

Do you think this Vehicle Signal specification needs enhancement? Do you want to discuss with experts? Try the following ressources to get in touch with the VSS community:
Enhancement request Create COVESA GitHub Issue
Join COVESA www.covesa.global
Discuss VSS on Slack w3cauto.slack.com
VSS Data Experts on Google Groups covesa.global data-expert-group

About VSS

The Vehicle Signal Specification (VSS) is an initiative by COVESA to define a syntax and a catalog for vehicle signals. The source code and releases can be found in the VSS github repository.

Supported datatypes

The following is a list of VSS supported built-in datatypes:

Name Type Min Max
uint8 unsigned 8-bit integer 0 255
int8 signed 8-bit integer -128 127
uint16 unsigned 16-bit integer 0 65535
int16 signed 16-bit integer -32768 32767
uint32 unsigned 32-bit integer 0 4294967295
int32 signed 32-bit integer -2147483648 2147483647
uint64 unsigned 64-bit integer 0 2^64 - 1
int64 signed 64-bit integer -2^63 2^63 - 1
boolean boolean value 0/false 1/true
float floating point number -3.4e -38 3.4e 38
double double precision floating point number -1.7e -300 1.7e 300
string character string n/a n/a

Min, max and default values defined in a Vehicle Signal Specification must be in the supported range of the data type.