Toyota Motor’s redesigned Lexus LS continues the flagship model line’s role as a technology leader, now combining various safety systems with the aim of eventually eliminating traffic-related deaths. Many of the systems carry over from the previous model but have been updated.
The new LS, on a new GA-L platform, goes on sale in Europe at the end of 2017 and again features the brand’s Safety System + and Safety System + A with enhancements including the Pre-Collision System (PCS), Lane Departure Alert (LDA) and Dynamic Radar Cruise Control.
The + A package includes Active Steering Assist, claimed as a world first, which helps prevent collisions that cannot be avoided through automatic braking alone, and Front Cross Traffic Alert (FCTA), which is designed to warn the driver of the possibility of head-on collisions at intersections. The system also includes CoDrive, which assists the driver to stay in lane.
New active safety technologies include Pre Collision System (PCS) with Pedestrian Alert and Active Steering Assist. Lexus claims Pedestrian Alert as a world first while Active Steering Assist automatically controls steering and braking. With Pedestrian Alert, if there is the possibility of collision with a pedestrian ahead, the direction of the pedestrian’s presence is shown in an animation on large colour head up display (HUD).
Active Steering Assist determines when there is a high possibility of collision with a pedestrian in the lane of travel or with a continuous structure, such as a guardrail, and if the system also determines that it is difficult to avoid a collision with brake control alone but that it might be avoided with steering control, the system assists in collision prevention or damage reduction through automatic steering control in addition to activating an alert and applying the brakes.
CoDrive adds Lane Tracing Assist (LTA) to the basic functions of Dynamic Radar Cruise Control to provide steering support on roads with many curves or in traffic jams, and is therefore claimed to largely decrease ‘driver burden’. It coordinates with the HUD and multi-information display to notify the driver of the state of support provided.
Lane Tracing Assist provides lane-keeping support by way of steering control when Adaptive Cruise Control is in operation. In addition to lane line detection by way of a camera, tracing of the path of the vehicle ahead enables assistance even when lane lines cannot be recognised, such as in low-speed driving in congestion when there is little distance to the preceding vehicle.
With eight LED lights at the top and 16 below (on each side), the Two-stage Adaptive High-beam System (AHS) provides optimal lighting by way of separate on/off control of each row of LEDs, enabling finer control of light strength and distance compared to the existing LED-based AHS. This allows higher frequency of high-beam driving without blinding preceding or oncoming vehicles, thus improving night-time visibility.
To help prevent collisions at intersections, Front Cross Traffic Alert (FCTA) is meant to detect forward cross-traffic vehicles. It uses forward direction radar and is claimed to be the first in the world to alert drivers of the direction from which a cross-traffic vehicle is approaching the immediate intersection. Alerts are displayed using the HUD. If the vehicle proceeds regardless of the presence of an approaching vehicle in cross traffic, warnings are also issued by a buzzer and the multi-information display.
Road Sign Assist (RSA) reads road signs using a camera and navigation maps and then displays them on the HUD and multi-information display. Ford has recently launched a system which can read the varying forms (by country) of variable speed limits displayed on overhead gantries, something Toyota RSA systems we’ve tried can’t yet do (they’re fine on fixed roadside signs) and it will be interesting to see if the latest LS system has been enhanced to meet this challenge.
Lexus has further evolved the performance of PCS, LDA and Dynamic Radar Cruise Control in Safety System +. Pre-Collision System (PCS) detects pedestrians and vehicles ahead using millimetre-wave radar and a stereo camera and supports collision prevention and damage mitigation with an alert, Pre-collision Brake Assist and Pre-collision Braking. The improved PCS can detect cyclists and night time pedestrians and has improved deceleration performance during automatic braking. For example, it can decelerate the vehicle by as much as 60 km/hour when a pedestrian is detected, thus improving its collision-prevention performance.
Lane Departure Alert (LDA) helps to prevent lane departures. In addition to detecting road lane lines, it is now also capable of detecting the boundaries between asphalt and such elements as grass, dirt and curbstone through advances in recognition capability.
Basic recognition performance has been improved with wide-angle detection using newly developed millimetre-wave radar and a camera with a wider forward recognition range. Dynamic Radar Cruise Control also provides smoother acceleration at start-up, and during following, departure and acceleration, smoother deceleration in the case of a rapid change in deceleration speed during following.
Lexus’ parking support brakes (stationary objects, vehicles approaching in the rear, pedestrians in the rear; also just introduced by Ford of Europe) are intended to reducing damage from accidents when parking and the system can spot moving vehicles and pedestrians, walls and other stationary objects. The low-speed braking support systems have been integrated into a single package added to the existing Intelligent Clearance Sonar (ICS) and Rear Cross Traffic Auto Brake (RCTAB). The claimed world first rear pedestrian support brake detects pedestrians using a rear camera and, in the case of a possible collision, helps to minimise damage by using alerts and brake control.
Side clearance view and cornering view functions have been added to the Panoramic View Monitor, which supports periphery safety checks. Side clearance view produces an image on the 12.3-inch display monitor of the area in front of the car as if it were seen from an elevated point at the rear of the car. When side clearance view is in operation, cornering view automatically produces an image of the vehicle as viewed from the rear at an angle in line with driving operation during cornering.