Long Distance EV Routing

Last edit: 2023.09.06

TomTom’s Long-Distance Electrical Vehicle Routing (LDEVR) algorithm uses the vehicle characteristics together with map data and live data services, such as TomTom Traffic, to reliably calculate the range and to select the most convenient charging stations along the way.

For the algorithm to work as accurately as possible, it needs to access data from the vehicle. Some data is more dynamic and can change while driving, per session or over the lifetime of the vehicle. Other data is typically static, such as vehicle dimensions. User behavior can also change the data, such as controlling HVAC or changing the drive mode from normal to sport.

To provide the data necessary for routing, the following two interfaces need to be implemented:

The Stock implementation of these interfaces in the TTDC platform provide static data that are read from the vehicle profile set in the The Debug Menu, which contains a number of pre-defined vehicle profiles. Optionally, some of the values can also dynamically be read from the Android Automotive Platform VHAL layer, set by the VehiclePropertyIds:

batteryChargeLevel is composed of INFO_EV_BATTERY_CAPACITY and EV_BATTERY_LEVEL
isChargingConnectorConnected is set by EV_CHARGE_PORT_CONNECTED
remainingRange is set by RANGE_REMAINING

Integrating Long Distance EV Routing in the vehicle

As the Stock implementation only provides debug values, it needs to be replaced by a custom one that can supply the data needed.

For more details on how to create an IVI service, see the Create an IVI Service page.

Depending on the OEM's implementation of the Android Automotive Platform and the hardware supplier, some of this data can be available in the VHAL. For example, battery level, battery capacity, and remaining range. Other data structures are more complex. The charging connectors, for example, are stored in a nested Set<>, and the charging curve is a data structure in a Set<>. Therefore, this data is unsuitable to be written/read through the Car API which only supports List<> and single values. This is better retrieved from other data providers.

In the VehicleSpecificationService the engineType needs to be set to VehicleEngineType.ELECTRIC to enable the EV features. The exteriorDimensions and the weight need to be set to the vehicle's physical dimensions and weight respectively.

The VehicleElectricEngineService interface requires the battery level and capacity to be set in the batteryChargeLevel property. Notably, most of the data can change while driving, for example the consumptionModel will change with the driving mode that the car is set to, for example eco drive, or sport drive. Note that the charging connectors that the car can utilize are necessary to be able to find suitable charging stations along the route. This data also needs to match the connectors available for the country map currently in use. The attributes required for this service are further documented in the API documentation for the interface: VehicleElectricEngineService.

Replacing the Stock implementation

When the custom service hosts have been implemented, the stock variants need to be replaced in the Gradle files:

build.gradle.kts:

1import com.tomtom.ivi.platform.gradle.api.defaults.config.vehicleSpecificationServiceHost
2import com.tomtom.ivi.platform.gradle.api.defaults.config.vehicleElectricEngineServiceHost
3
4ivi {
5    application {
6        enabled = true
7        services {
8            removeHost(vehicleSpecificationServiceHost)
9            removeHost(vehicleElectricEngineServiceHost)
10            // Add your own service hosts
11            // ...
12
13            addHost( /* your own vehicle specification host */ )
14            addHost( /* your own vehicle electric engine host */ )
15
16            // etc...