Outline · [ Standard ] · Linear+ Renault: FOUR-WHEEL ACTIVE DRIVE CHASSIS, info.

FOUR-WHEEL ACTIVE DRIVE CHASSIS: INTENSE DRIVING PLEASURE AND UNQUALIFIED EFFICIENCY Renault will unveil a sneak preview of its four-wheel Active Drive chassis to visitors to the Frankfurt Motor Show. This brand new technology, jointly developed by Renault and Renault Sport Technologies on New Laguna, guarantees greater handling responsiveness, more dynamic performance and driving precision, all of which combine to deliver the ultimate in driving pleasure. The four-wheel Active Drive chassis features a number of advantages. Aside from increased handling responsiveness and an even more stable ride, New Laguna offers an unrivalled level of steering precision, which instinctively sets the vehicle on the right trajectory, producing remarkable levels of driving comfort and active safety. Even at very low speeds, the system is immediately operational and surprisingly effective. The vehicle thus becomes easy to drive on both city streets and winding country roads, its handling responsive and precise. Using specific settings, Laguna’s remarkable road-holding provides its occupants with the feeling of a car that stays level throughout bends. Drivers will enjoy the absence of any temporary drop in handling performance as they negotiate corners and the precision of the narrow steering wheel angles. In terms of active safety, the four-wheel Active Drive chassis excels not only in testing braking conditions (irregular grip, activation of ESP to control trajectory), but also when drivers are forced to swerve suddenly (moose test). Handles likes a compact city car New Laguna handles more responsively both on urban and winding country roads, thanks to its four-wheel Active Drive chassis. At speeds below 60kph, the rear wheels can turn in the opposite direction to those at the front, to a maximum angle of 3.5°. The four-wheel Active Drive chassis offers two key advantages: easier handling thanks to a smaller turning circle and reduced steering wheel angles thanks to a more direct, specifically configured steering system. To start with, New Laguna’s turning circle is reduced by 10% on the 18-inch wheel version of the four-wheel Active Drive chassis: it drops from 12.05m to a mere 10.80m. This means that the wider the angle behind the wheels, the smaller the turning circle becomes. This easier handling is felt most acutely when exiting a parking space or when negotiating narrow streets. Secondly, as the wheel lock of the front and rear wheels may be combined, the four-wheel Active Drive system produces more tightly-geared steering. Whereas on a normal New Laguna a 16 degree angle is required on the steering wheel in order to produce 1° on the wheels, only 13.5° are needed with the Active Drive chassis. The ratio becomes an even more impressive 1:12 when the rear wheels are in opposing phases, at a maximum angle of 3.5°. The more direct steering means significantly less effort is needed to steer the vehicle. Drivers therefore need to turn the wheel less to negotiate corners and can instead enjoy the increased handling responsiveness and agility. Thanks to the rear wheel lock, it becomes easier to get past obstacles - the vehicle appears to wrap itself around anything in its way. Unerring steering precision Above 60kph, New Laguna offers greater driving precision. The car boasts improved stability and handles as if it is running on rails. By simultaneously turning the front and rear wheels in the same direction, the four-wheel Active Drive system counters the centrifugal force that tends to cause the rear of the car to drift wide on corners (rear axle offset). The system ensures increased cornering speeds. It takes New Laguna’s road-handling ability to new heights without stiffening the suspension, which would sacrifice overall comfort. With a wheel turning angle which is usually less than 2°, the rear axle is instantly set to the ideal trajectory, improving stability and efficiency. In emergency situations (sudden swerving), the wheel can turn up to 3.5°. The four-wheel Active Drive chassis affords greater dynamic performance and delivers greater driving pleasure, whilst guaranteeing an even ride and giving occupants greater peace of mind. An unrivalled level of active safety The four-wheel Active Drive chassis also gives drivers a greater sense of security and assurance when they are forced to swerve suddenly. As it keeps a record of all previous steering wheel angles, the four-wheel Active Drive ECU is able to detect situations where the car is about to swerve suddenly (characterized by large variations between two steering wheel angle readings taken in quick succession) and adapts the angle of the rear wheels accordingly. As the settings of the Active Drive system are specifically-adapted for dynamic, sporty driving, activation of ESP is delayed. This means drivers know they can swerve at higher speeds and, more importantly, with greater security. ESP is only activated when necessary, and very gradually, since the rear wheels are also turned as necessary. The four-wheel Active Drive ECU also detects asymmetrical braking situations by working in conjunction with the ESP/ABS unit. It adapts the angle of the rear wheels so that the car remains stable without the driver having to turn the steering wheel. The driver therefore keeps control of the vehicle in critical situations, which gives him or her greater peace of mind at the wheel. A mechanical system with dynamic logic Jointly developed by Renault and Renault Sport Technologies engineers, the fourwheel Active Drive chassis uses an electronic control system to manage the dynamic ride of the vehicle. The steering column-mounted sensor sends data about the steering wheel angle via the CAN network to the ECU. The ECU, located behind the rear axle, also receives information about the vehicle’s speed from the ESP/ABS unit. The ECU is capable of comparing steering wheel angle values over time, which means it can detect the high steering wheel speeds that go hand in hand with sporty driving or sudden swerving manoeuvres. Based on the information received, the ECU issues the appropriate rear-wheel steering command to the electrical actuator, located on the rear axle. The precise modelling of the vehicle’s dynamic ride enables the ideal trajectory to be continuously maintained, using information provided by driver requests or from the real-life situation of the vehicle. The four-wheel Active Drive chassis will be available with certain powertrain packages on the new versions and sub-models of New Laguna from spring 2008. sursa: renault.com

FOUR-WHEEL ACTIVE DRIVE CHASSIS:

INTENSE DRIVING PLEASURE AND UNQUALIFIED EFFICIENCY

Renault will unveil a sneak preview of its four-wheel Active Drive chassis to visitors to the Frankfurt Motor Show. This brand new technology, jointly developed by Renault and Renault Sport Technologies on New Laguna, guarantees greater handling responsiveness, more dynamic performance and driving precision, all of which combine to deliver the ultimate in driving pleasure.

The four-wheel Active Drive chassis features a number of advantages. Aside from increased handling responsiveness and an even more stable ride, New Laguna offers an unrivalled level of steering precision, which instinctively sets the vehicle on the right trajectory, producing remarkable levels of driving comfort and active safety. Even at very low speeds, the system is immediately operational and surprisingly effective. The vehicle thus becomes easy to drive on both city streets and winding country roads, its handling responsive and precise. Using specific settings, Laguna’s remarkable road-holding provides its occupants with the feeling of a car that stays level throughout bends. Drivers will enjoy the absence of any temporary drop in handling performance as they negotiate corners and the precision of the narrow steering wheel angles. In terms of active safety, the four-wheel Active Drive chassis excels not only in testing braking conditions (irregular grip, activation of ESP to control trajectory), but also when drivers are forced to swerve suddenly (moose test).

Handles likes a compact city car

New Laguna handles more responsively both on urban and winding country roads, thanks to its four-wheel Active Drive chassis. At speeds below 60kph, the rear wheels can turn in the opposite direction to those at the front, to a maximum angle of 3.5°.

The four-wheel Active Drive chassis offers two key advantages: easier handling thanks to a smaller turning circle and reduced steering wheel angles thanks to a more direct, specifically configured steering system. To start with, New Laguna’s turning circle is reduced by 10% on the 18-inch wheel version of the four-wheel Active Drive chassis: it drops from 12.05m to a mere 10.80m. This means that the wider the angle behind the wheels, the smaller the turning circle becomes. This easier handling is felt most acutely when exiting a parking space or when negotiating narrow streets. Secondly, as the wheel lock of the front and rear wheels may be combined, the four-wheel Active Drive system produces more tightly-geared steering. Whereas on a normal New Laguna a 16 degree angle is required on the steering wheel in order to produce 1° on the wheels, only 13.5° are needed with the Active Drive chassis. The ratio becomes an even more impressive 1:12 when the rear wheels are in opposing phases, at a maximum angle of 3.5°. The more direct steering means significantly less effort is needed to steer the vehicle. Drivers therefore need to turn the wheel less to negotiate corners and can instead enjoy the increased handling responsiveness and agility. Thanks to the rear wheel lock, it becomes easier to get past obstacles - the vehicle appears to wrap itself around anything in its way.

Unerring steering precision

Above 60kph, New Laguna offers greater driving precision. The car boasts improved stability and handles as if it is running on rails. By simultaneously turning the front and rear wheels in the same direction, the four-wheel Active Drive system counters the centrifugal force that tends to cause the rear of the car to drift wide on corners (rear axle offset). The system ensures increased cornering speeds. It takes New Laguna’s road-handling ability to new heights without stiffening the suspension, which would sacrifice overall comfort. With a wheel turning angle which is usually less than 2°, the rear axle is instantly set to the ideal trajectory, improving stability and efficiency. In emergency situations (sudden swerving), the wheel can turn up to 3.5°. The four-wheel Active Drive chassis affords greater dynamic performance and delivers greater driving pleasure, whilst guaranteeing an even ride and giving occupants greater peace of mind.

An unrivalled level of active safety

The four-wheel Active Drive chassis also gives drivers a greater sense of security and assurance when they are forced to swerve suddenly. As it keeps a record of all previous steering wheel angles, the four-wheel Active Drive ECU is able to detect situations where the car is about to swerve suddenly (characterized by large variations between two steering wheel angle readings taken in quick succession) and adapts the angle of the rear wheels accordingly. As the settings of the Active Drive system are specifically-adapted for dynamic, sporty driving, activation of ESP is delayed. This means drivers know they can swerve at higher speeds and, more importantly, with greater security. ESP is only activated when necessary, and very gradually, since the rear wheels are also turned as necessary. The four-wheel Active Drive ECU also detects asymmetrical braking situations by working in conjunction with the ESP/ABS unit. It adapts the angle of the rear wheels so that the car remains stable without the driver having to turn the steering wheel. The driver therefore keeps control of the vehicle in critical situations, which gives him or her greater peace of mind at the wheel.

A mechanical system with dynamic logic

Jointly developed by Renault and Renault Sport Technologies engineers, the fourwheel Active Drive chassis uses an electronic control system to manage the dynamic ride of the vehicle. The steering column-mounted sensor sends data about the steering wheel angle via the CAN network to the ECU. The ECU, located behind the rear axle, also receives information about the vehicle’s speed from the ESP/ABS unit. The ECU is capable of comparing steering wheel angle values over time, which means it can detect the high steering wheel speeds that go hand in hand with sporty driving or sudden swerving manoeuvres. Based on the information received, the ECU issues the appropriate rear-wheel steering command to the electrical actuator, located on the rear axle. The precise modelling of the vehicle’s dynamic ride enables the ideal trajectory to be continuously maintained, using information provided by driver requests or from the real-life situation of the vehicle.
The four-wheel Active Drive chassis will be available with certain powertrain packages on the new versions and sub-models of New Laguna from spring 2008.

sursa: renault.com