T EC H TALK
Terrain Response Control
by Charita Ratnatunga
In the beginning getting out of the vehicle and locking the hubs was a common practice. If forgotten, it meant driving
in low range in two wheel drive. That was the first generation of 4WD vehicles.
Then came the auto hubs and the secondary mechanical gear selector which evolved to an electronic gear selector.
Add in the traction control system and we are getting into the modern era of 4WD technology.
However, there is a big problem!! Traction control systems are designed to limit wheel slip and get the vehicle moving
progressively in one direction. If the system is unaware of the terrain, the vehicle will try to only limit wheel slip and
if that doesn’t work, the system will give up!
If the vehicle is aware of the surface type (terrain), then the traction control, engine RPM, gear change and throttle
operations can be all optimised. The Terrain Management System (TMS) simply does this activity.
The 4WD driving skills in the future will focus more on knowing what settings are available and making the most
appropriate selection. The driver may not even need to be seated in the car. Land Rover are developing Remote Car
Control technology that will enable the driver to drive the car using a smartphone from outside the car.
What is a Terrain Management System (TMS)?
A TMS optimises the vehicle settings to provide the best outcome based on the selection made by the driver.
How does a Terrain Management System Work?
Based on the selection made, the vehicle will control engine RPM, gear changes, throttle response and traction
control. The vehicle has built in algorithms that will set the vehicle dynamics for each mode selected by the driver.
The elements of the vehicle dynamics are mentioned below and they all have to work in tandem to deliver the best
result.
Engine RPM - controlling the engine RPM will deliver the required torque in all conditions
Throttle Response – adjusting throttle sensitivity is required for different terrain such as sand or rocks.
Gear Change – Driving in different terrain requires the vehicle to hold the gear and make quick changes as engine
RPM changes.
Traction Control – Traction Control can control the when slip, when in steep rocky terrain or allow more wheel slip
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Vol 34 No. 4 - May 2017