The new lexus gs 2012: safety
• Advanced Pre-Crash Safety (PCS) system incorporating Driver Monitor Camera
• Adaptive Cruise Control (ACC) system now functions at all speeds down to 0km/h
• Step 5 Vehicle Dynamics Integrated Management (VDIM) integrating Lexus Dynamic Handling (LDH) system
• Lane-Keep Assist (LKA) and Blind Spot Monitor (BSM) systems
• Lexus Night View system
• Head-Up Display (HUD) with an expanded content menu including tachometer information
• Intelligent Adaptive Front-lighting (I-AFS) with Automatic High Beam
• Enhanced Pedestrian Protection
• 10 airbags and rear seatbelt pre-tensioners
• Emergency Stop Signal Lamp
The new Lexus GS is comprehensively equipped with the most technologically advanced pre-emptive, active and passive safety and driver assistance systems available on the market today.
An Advanced Pre-Crash Safety (PCS) system incorporates a Driver Monitor Camera. PCS pre-emptively optimises front seat belt and emergency braking systems to help reduce collision damage and injury. A complementary Adaptive Cruise Control (ACC) system, now available on the GS 450h, functions at all speeds down to 0km/h.
The GS features the latest, Step 5 generation of Lexus' state-of-the-art Vehicle Dynamics Integrated Management (VDIM), which now integrates the newly developed Lexus Dynamic Handling (LDH) system.
Additional active safety features include a Lane-Keep Assist (LKA) system, a Blind Spot Monitor (BSM) system, the Lexus Night View system, and a Head-Up Display (HUD) with an expanded content menu.
The new Lexus benefits from no less than 10 airbags, and rear seatbelt pre-tensioners are fitted as standard. Intelligent Adaptive Front Lighting (I-AFS) enhances visibility through bends, whilst the new GS's front bumper, cowl and corrugated sheet bonnet have been carefully designed to offer enhanced pedestrian protection in the event of a collision.
Advanced Pre-Crash Safety (PCS)
The new GS is equipped with a sophisticated, Advanced Pre-Crash Safety (PCS) system that can help reduce collision damage and injury. The PCS system features a millimetre-wave radar sensor, operating within a 20 degree scanning radius to detect obstacles in front of the car, even during cornering.
Via numerous sensors, a pre-collision system computer monitors vehicle speed, steering angle and yaw rate inputs to help determine in advance whether an impending collision is unavoidable.
If there is a high possibility of a collision, PCS will alert the driver via both a buzzer and a warning on the multi-information display, activate the Pre‑Crash Seatbelt pretensioners to retract all slack from the front belts and, when he begins to brake, provide Pre-Crash Brake Assist to supplement his own braking effort.
In addition, PCS implements a close interaction between the Variable Gear Ratio Steering (VGRS) and Dynamic Rear Steering (DRS) incorporated within the GS's Step 5 Vehicle Dynamics Integrated Management (VDIM) system, improving the vehicle's response to the driver's emergency steering inputs to increase the chances of avoiding the obstacle.
If the driver does not brake and a collision is inevitable, Pre-Crash Brake will automatically apply the brakes to reduce impact speed.
PCS has been revised in the new GS. The timing of brake intervention has been increased from 0.8 to 1.2 seconds before anticipated impact, both improving the chances of avoiding a frontal collision and, in the event of impact, lowering the collision speed by about 15km/h to greatly reduce vehicle damage.
Driver Monitor Camera
The Advanced Pre-Crash Safety system also incorporates a Driver Monitor Camera. The system employs two near-infrared LEDs and a CCD camera built into the top of the steering column. Monitoring various aspects of the driver's face including the degree of eye opening, the system is able to determine if the driver's eyes are closed. If this is the case when there is a danger of collision, the timing of the Pre-Crash warning sequence is brought forward to alert the driver in good time.
All-speed Adaptive Cruise Control (ACC)
Complementary to the PCS system, the new GS features an Adaptive Cruise Control (ACC) system. The system offers two modes: constant speed control, and vehicle-to-vehicle distance control. Operational at speeds over 50km/h, the constant speed control functions in the manner of a conventional cruise control system.
Capable of differentiating between vehicles directly ahead of the Lexus and those in an adjacent lane, the vehicle-to-vehicle distance control system employs the PCS millimetre-wave radar sensor, allied to constant speed, decelerator, follow-up and accelerator controls, to automatically slow the GS, match the speed of the vehicle in front and, once the road is clear ahead, accelerate to the previously selected cruising speed.
Exclusive to the GS 450h, ACC is now capable of operating at all speeds down to 0km/h. After a complete stop, and then restart of the preceding vehicle, the GS's driver need only press the accelerator briefly to reactivate ACC's tracking of the car in front.
Vehicle Dynamics Integrated Management (VDIM) Step 5
The new GS features the latest, Step 5 generation 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 integrates the GS's Electronically Controlled Brake (ECB) four-wheel independent braking, Anti-Lock Brakes (ABS), Electronic Brakeforce Distribution (EBD), Traction Control (TRC) and Vehicle Stability Control (VSC) active safety systems with the Electronic Power Steering (EPS), Variable Gear Ratio Steering (VGRS), Adaptive Variable Suspension (AVS) and —for the first time- Dynamic Rear Steering (DRS) systems.
Whilst the current generation GS's VDIM system can help restrain vehicle yaw and roll motion through control of the AVS and VGRS, the newly developed Step 5 incorporates the Lexus Dynamic Handling (LDH) system. This enables the VDIM system to control the steering angle of all four wheels, achieving the ideal slip angle to help govern the lateral motion of the vehicle for added stability when, for instance, there is a risk of understeer or oversteer when cornering, or when braking on a road surface with differing levels of grip between the left and right wheels.
By the application of integrated control of all the elements related to vehicle movement, including motor torque, brakes and steering, VDIM not only optimises the activation of braking, stability and traction control systems, 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 performance envelope has been reached, VDIM activates control before that limit is realised. As a result, the limits of the vehicle's performance threshold have been expanded, whilst offering smoother vehicle behaviour at this threshold through less obtrusive intervention and, hence, a more pleasurable drive.
Lane-Keep Assist (LKA) system
With lane marker detection provided by an on-board camera, the new GS is equipped with a Lane—Keep Assist (LKA) system to help keep the driver from drifting out of his lane.
Now offering smoother steering corrections, the system calculates the steering torque input required based on the results of lane-marker detection, and automatically generates appropriate torque.
Blind Spot Monitor (BSM) system
The Blind Spot Monitor (BSM) system uses radar devices mounted on the corners of the rear bumper to detect overtaking vehicles in adjacent lanes.
Operating if the GS's speed is greater than 40km/h and the relative speed of the two vehicles is less than approximately 28km/h, the system activates a warning via an indicator lamp in the outer door mirror. If the turn signal indicators are operating at the time, the warning lamp will flash at a faster 4.0Hz frequency than the 1.7Hz of the turn signal lamps to alert the driver.
Lexus Night View system
The Lexus Night View system combines a windscreen head-mounted near-infrared camera and infrared LED lamps mounted within the headlight clusters with a Night View ECU to display an image of the road ahead on the GS's 12.3" centre console display screen.
The system will operate at speeds of between 15 and 80km/h, displaying an area up to 200 metres in front of the vehicle.
Head-Up Display (HUD)
White readouts on the Head-Up Display project key GS driving data into the driver's line of sight on the base of the windscreen, including vehicle speed, turn-by-turn navigation, audio, Adaptive Cruise Control and Pre‑Crash Safety system status. For the first time on a Lexus, the display also now includes tachometer information.
The HUD's white readouts use high-intensity LEDs to provide ample clarity and visibility, and it is extremely easy to use. Pressing and releasing the HUD main switch turns it on and off cyclically. The display position can also be adjusted, as can light intensity, which may also be adjusted automatically to the ambient light.
Adaptive Front-lighting System (AFS) with Automatic High Beam
The new GS features an Adaptive Front-lighting System (AFS), which automatically swivels the headlamp beam, helping to illuminate a bend as the driver steers into it.
The new system features a more advanced swivel control, increasing the swivel angle of one headlamp only at low speeds to enhance intersection visibility, whilst swivelling both beams at higher speeds for improved visibility and reduced glare for oncoming vehicles.
Through the combination of AFS and Dynamic Rear Steering (DRS), swivel control has now been developed to monitor front and rear wheel steering angle difference, as well as vehicle speed.
The headlamps also feature an Automatic High Beam system. A camera located in the inner mirror detects light sources in front of the new GS -including the headlamps of oncoming vehicles, the tail lamps of a vehicle ahead and street lighting- and the system will automatically switch the high beams on and off accordingly, obviating the need for manual operation of the dimmer switch.
Emergency Brake Signal
The new GS features an Emergency Brake Signal system. Based on information from the acceleration sensor, wheel speed sensor and brake pedal switch, the system monitors vehicle status and the driver's brake operation, automatically flashing the brake lamps during emergency braking.
By adopting an LED light source, the response speed of the brake lamps has been significantly improved, alerting the driver behind as quickly as possible to help prevent rear-end collisions.
Tyre Pressure Monitor (TPM)
A Tyre Pressure Monitor (TPM) can detect a loss of pressure in one or more tyres. Notifying the driver via a dashboard mounted warning light, the system will highlight any tyres affected by low pressure, indicating the current pressure.
Reflecting the stringent car-to-car impact compatibility standards unique to the Lexus marque, the new GS has been created with the express aim of achieving class-leading safety in full-frontal, offset, side-on and rear collisions.
The comprehensive use of high- and ultra-high-tensile steel within the body structure optimally transfers and disperses impact load, minimising cabin deformation during a collision and maintaining space for the occupants.
Particular attention has been paid to side impact protection, with ultra-high-tensile steel adopted for rocker outer reinforcement, the rear door impact beam sheet thickness increased, and Lexus' first use of hot press sheet steel in the construction of the B Pillar.
During the die moulding of hot press steel, firing and quenching occur at the same time as pressing, both enabling the creation of profiles that would be difficult to form with cold sheet steel, and increasing the strength of the material itself.
The new GS's front bumper, cowl and corrugated sheet bonnet have been carefully designed to offer enhanced pedestrian protection in the event of a collision.
The bead height and pitch of the corrugated bonnet design have been optimised with a new, thinner design. The frontal bonnet structure has been designed to easily deform on contact with a pedestrian's upper legs, and a gap between the bonnet and the top of headlamps helps reduce the force of a head impact.
Impact absorbing materials built into the front bumper help reduce the load applied to a pedestrian's legs. And the front wings incorporate a new, head impact alleviating structure.
Both the cowl panel area and cowl louvre adopt easily deformed structures with deformation controlled by the use of different sheet thicknesses.
The Lexus GS benefits from 10 airbags; two-stage Dual Supplementary Restraint System (SRS) front airbags, both driver and front passenger knee airbags (the latter installed in the glove box door), front and rear side airbags, as well as both front and rear side curtain airbags.
The advanced, Supplementary Restraint System controls variable-force front airbags for both driver and front passenger. Sensors determine the severity on an impact and, hence, the force with which the airbags are deployed.