Electrical suspension gives smoother ride

Researchers at the University of Texas have developed and demonstrated an electrical suspension system that may replace conventional springs and shock absorbers.

An electrical suspension system for cars and trucks developed by researchers at The University of Texas at Austin has demonstrated a fivefold reduction of shock and vibration to the passengers, double the off-road top speed and better handling in cornering, all resulting in improved off-road fuel economy.

Researchers at the Centre for Electromechanics of the University of Texas at Austin designed the electrical system to replace conventional systems composed of springs and shock absorbers.

Tests conducted over the last two years at the US Army’s Yuma Proving Grounds reportedly showed significant improvement over conventional systems.

The University of Texas at Austin researchers installed the system on a High Mobility Multipurpose Wheeled Vehicle (HMMWV) supplied by the Army and was tested on off-road courses where the electrical suspension demonstrated a fivefold reduction in the shock and vibration delivered to the driver, passengers or load.

Because of this reduction, a very smooth ride could be maintained at normal speeds, making tasks such as writing or operating laptop computers much more convenient. Alternatively, if the normal bounce is tolerable, the speed can be doubled.

Improved stability during cornering and braking was achieved through control of the vehicle’s height, pitch and roll.

Traditionally, vehicles with comfortable rides have soft suspension systems that are said to minimise ride vibrations but are difficult to manoeuvre due to excessive pitch and roll. At the other extreme, stiff suspensions have good handling but provide a bumpy ride.

The electrical suspension uses a soft spring to provide a good ride and an electromechanical system to minimise pitch and roll for improved handling. Moreover, dynamic adjustment of the vehicle’s centre of gravity during turning reduces rollover risk.

The improved fuel economy occurs because the active suspension system is said to consume significantly less power than today’s system when used on rough roads or in off-road uses.

The amount of savings is highly dependent on specific driving conditions, including the roughness of the route. But in one set of tests, the newly developed suspension appeared to be about 30 percent more efficient than existing systems.

The key components of the university-developed system are an electric motor driving a rack and pinion at each wheel, accelerometers and an advanced control system.

The electrical and mechanical components were designed so they could be assembled using commercially available parts. The sensing and control software were developed and optimised specifically for this application.