Land Rover Concept

07Dec07

Land Rover Concept SUV

Land Rover Concept SUV

The importance of the Land_e are the relevant technologies it showcases. The Land_e targets a sub 150g/km CO2 figure. Representing an improvement of almost 30 per cent on today’s figures.

Integrated Electric Rear Axle Drive enhances off-road performance by augmenting rather than replacing the mechanical drive. Off-road, the Integrated Electric Rear Axle Drive system can provide additional torque.  Electric power provides maximum torque from standstill. Offering better low-speed control and pull-away in difficult situations – such as on slippery surfaces or when towing.

On-road, the additional low-speed torque allows electric-powered ‘traffic creep’ and low-speed acceleration up to 20 mph, without restarting the engine. When quick acceleration is demanded, the engine restarts immediately, so both the engine and the electric motor supply power. In this case, the electric torque boost improves acceleration without adversely affecting either fuel consumption or CO2 emissions.

Energy is stored in a lithium-ion battery pack which is charged by regenerative braking energy. Pressing the brake pedal causes the driveshafts and propshaft to transfer energy from the wheels to the Integrated Electric Rear Axle Drive system, decelerating the vehicle and transferring the ‘braking’ energy to the storage battery. For harder braking and for emergency stops, the conventional braking system is retained, working in conjunction with the regenerative braking function.

The Integrated Starter-Generator system replaces the conventional alternator. The ‘micro-hybrid’ system shuts the engine down automatically whenever the vehicle stops, as in traffic. When required the ECU restarts the engine quickly and smoothly.

The stop-start function of ISG and the regenerative braking function from the Integrated Electric Rear Axle Drive offer the potential of a 20 per cent reduction in CO2 emissions.

Seamless re-connect reduces fuel consumption by cutting mechanical losses. Drive to the rear wheels is automatically disconnected when conditions allow, such as cruising on a dry surface. When rear drive is required the system reconnects the rear axle automatically and virtually instantaneously.

The ISG system, Integrated Electric Rear Axle Drive and the Seamless Re-connect propshaft are fully compatible with all Land Rover engine and transmission options, and could be adapted for any model and any market.

Land_e shows six Terrain Response modes: The new e-Mode focuses principally on on-road use. This configures all the vehicle’s e-terrain systems for optimised fuel economy. It retains instantaneous access to four-wheel drive but adopts soft throttle responses, and delivers early shift points. The other five modes are already available on some Land Rover products – General Driving; Sand; Mud and Ruts; Grass, Gravel and Snow; and Rock Crawl. In all off-road modes, the engine is never shut down, even when the vehicle is stationary.

Beyond the efficiency-enhancing drivetrain technology, the Land_e showcases other fuel saving technologies. The Intelligent Thermal Program controls exhaust heat management and the cooling system. Through heat exchangers, the Exhaust Heat Recovery System uses the heat from the exhaust system to warm-up the engine and gearbox faster. ITP could also control Active Aero Vanes, which would allow specific sections of the radiator aperture to be closed. Reducing drag when cooling air is not needed. The vanes would also be closed during engine warm-up, again to ensure that the engine reaches optimum operating temperature as quickly as possible. Faster engine and catalyst warm-up significantly reduces emissions in the first minutes after a cold start, and by bringing oil up to operating temperature more quickly, it reduces mechanical friction.

Electronically controlled thermostat and cooling circuit give more accurate temperature figures ensuring the engine runs as close to its optimum temperature as possible. The system incorporates an electric water pump, which is only driven on demand, and at variable speeds, avoiding inefficiency.

EPAS (Electric Power Assisted Steering) completely eliminates the hydraulic assistance of a conventional system and powers the steering rack directly, by electric servo motor. Eliminating pumping power losses, including the significant losses when the pump is being driven at high speed even though assistance is not required, offers a noticeable CO2 benefit compared to a hydaulic system.

All electrical system functions are controlled by IMES (Intelligent Management of Electrical Systems). It monitors battery charge, vehicle electrical system demands, and generator speed and load. It uses the data to ensure the electrical system operates in the most efficient way. It charges the battery only when needed, avoiding over-charging associated with conventional systems. Unless it is absolutely necessary, it avoids charging the battery when it is in ‘low-acceptance’ states – such as cold ambient conditions.

An increasing emphasis on diesel power is clearly important to overall CO2 reductions. Bio-diesel is a fuel derived from renewable and sustainable sources, such as natural oils from soya beans or other easily cultivated vegetable or cereal crops. It is currently commercially available as a blend of bio-derived diesel and petroleum-derived diesel, in varying proportions, and bio-diesel offers reduced emissions compared with petroleum-derived diesel.

Currently, a five per cent bio-derived content is typical with forecourt diesel. Potentially, a vehicle could operate on a 25 per cent bio-diesel mix, which is a realistic goal within a few years, and one supported by the oil industry and governments. A vehicle running on 25 per cent bio-diesel mix could potentially reduce its CO2 emissions by up to 25 per cent. Next generation bio-fuels made from crop wastes are also being developed, and these will deliver even greater CO2 reductions, as well as being more sustainable.

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