AVS automatically adjusts the damping force of the suspension at all four wheels independently. The system monitors data from engine speed, front wheel speed, steering, stop lamp and three vertical acceleration, G-force sensors to continuously adjust the damping force of each shock absorber through 9 incremental steps.

Hence, in response to driving operation, vehicle body motion and road surface conditions, AVS activates the adjustable damping force shock absorbers to fulfil a wide range of specific control functions, including vehicle speedsensitive damping force and body control (dive, squat and roll).

In addition, an advanced non-linear H control logic can improve ride comfort in particular situations. The vertical acceleration sensors monitor the body vertical movements, allowing the AVS ECU to determine when this will be exposed to vibration frequencies that will cause repercussions (disturbances that create additional vibration) and cause a rough ride impression. In these circumstances, an adequate, lower damping force will be selected, enabling a flatter ride.

The non-linear H control logic has clear advantages over the conventional Skyhook linear control by providing a more efficient response to transient situations, reflected on a better dampening of the body vertical movement.

In addition, AVS cooperates with VDIM (Vehicle Dynamics Integrated Management) and PCS (Pre-Crash Safety) to adopt a stiffer shock absorber setting during the activation of these systems.



Safety

The new Lexus GS 450h high-performance luxury sedan is comprehensively equipped with
the most technologically advanced pre-emptive, active and passive safety systems available on
the segment today.


ACTIVE SAFETY

Vehicle Dynamics Integrated Management (VDIM)

The new GS 450h features the most advanced version of Lexus' state-of-the-art Vehicle Dynamics Integrated Management (VDIM) system, to enhance performance, traction control and vehicle stability. With comprehensive status data provided by sensors throughout the vehicle, VDIM compares driver's actions (steering, accelerating, braking, gearshifting) with the trajectory of the vehicle (longitudinal and side acceleration, yaw rate and wheel speed). Then, VDIM will act on matching the vehicle dynamics to the intention of the driver, as much as possible.

VDIM's operation integrates the GS 450h's Electronically Controlled Braking (ECB) by-wire system, Anti-Lock Brakes (ABS), Electronic Brakeforce Distribution (EBD), Traction Control (TRC) and Vehicle Stability Control (VSC) with the Electronic Power Steering (EPS) and Variable Gear Ratio Steering (VGRS) systems. In addition, VDIM also communicates with the Adaptive Variable Suspension (AVS) to prompt a stiffer shock absorber setting to both optimise body control under extreme conditions and minimise vehicle nose diving under emergency braking.

By the application of integrated control of all the elements related to vehicle movement, including the hybrid system's electric motor torque, brakes and steering, VDIM not only improves active safety, but is also able to further improve the overall kinetic performance of the vehicle.

Moreover, whereas conventional safety systems are only activated immediately after a limit of the vehicle's perfomance envelope has been reached, VDIM activates control before that limit is realised.

For example, on a road surface with differing degrees of grip on either side of the vehicle, sudden braking will cause the vehicle to pull towards the side with the higher friction coefficient. As well as controlling wheel speed on an independent basis, VDIM activates the VGRS system to automatically regulate the steering angle and counteract the disparate, left and right-side braking forces, minimising the driver steering input necessary to maintain straight line braking. Similarly, when differing degrees of road surface grip cause the vehicle to pull towards the side of the lower friction coefficient under acceleration, VDIM automatically regulates the steering angle to maintain vehicle stability with minimum driver input.

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