page_title: Collision avoidance system
section_title: Toyota
hierarchical_section_title: Collision avoidance system / Automobile manufacturers / Toyota
caption_attribution_description: Lexus LS Pre-Collision System; showing radar sensors (blue) / infrared stereocameras (red)
context_page_description: A collision avoidance system, also known as a pre-crash system, forward collision warning system, or collision mitigation system, is an automobile safety system designed to prevent or reduce the severity of a collision. In its basic form, a forward collision warning system monitors a vehicle's speed, the speed of the vehicle in front of it, and the distance between the vehicles, so that it can provide a warning to the driver if the vehicles get too close, potentially helping to avoid a crash. Various technologies and sensors that are used include radar and sometimes laser and camera to detect an imminent crash. GPS sensors can detect fixed dangers such as approaching stop signs through a location database. Pedestrian detection can also be a feature of these types of systems.
  Collision avoidance system range from widespread systems mandatory in some countries, such as Autonomous Emergency Braking in the EU, agreements between automakers and safety officials to make crash avoidance systems eventually standard, such as in the United States, to research projects including some manufacturer specific devices.
context_section_description: Toyota's pre-collision system (PCS) is a radar-based system that uses a forward-facing millimeter-wave radar. When the system determines that a frontal collision is unavoidable, it preemptively tightens the seat belts, removing any slack, and pre-charges the brakes using brake assist to give the driver maximum stopping power when the driver depresses the brake pedal.
  2003 February: Toyota launched PCS in the redesigned Japanese domestic market Harrier.
  2003 August: added an automatic partial pre-crash braking system to the Celsior.
  2003 September: PCS made available in North America on the Lexus LS 430, becoming the first radar-guided forward collision warning system offered in the US.
  2004: In July 2004, the Crown Majesta radar PCS added a single digital camera to improve the accuracy of collision forecast and warning and control levels
  2006: Pre-collision system with Driver Monitoring System introduced in March 2006 on the Lexus GS 450h using a CCD camera on the steering column. This system monitors the driver's face to determine where the driver is looking. If the driver's head turns away from the road and a frontal obstacle is detected, the system will alert the driver using a buzzer, and if necessary, pre-charge the brakes and tighten the safety belts.
  2006: the Lexus LS introduced an advanced pre-collision system (APCS), added a twin-lens stereo camera located on the windshield and a more sensitive radar to detect smaller "soft" objects such as animals and pedestrians. A near-infrared projector located in the headlights allows the system to work at night. With the adaptive variable suspension (AVS) and electric power steering, the system can change the shock absorber firmness, steering gear ratios, and torque assist to aid the driver's evasive steering measures. The lane departure warning system will make automatic steering adjustments to help ensure that the vehicle maintains its lane in case the driver fails to react. Driver Monitoring System was introduced on the Lexus LS. Rear-end pre-collision system includes a rearward-facing millimeter-wave radar mounted in the rear bumper. The system adjusts the active head restraints by moving them upward and forward to reduce the risk of whiplash injuries if an imminent rear collision is detected.
  2008: Improved Driver Monitoring System added on the Crown for detecting whether the driver's eyes are properly open. It monitors the driver's eyes to detect the driver's level of wakefulness. This system is designed to work even if the driver is wearing sunglasses, and at night.
  2008: PCS with GPS-navigation linked brake assist function on the Crown. The system is designed to determine if the driver is late in decelerating at an approaching stop sign, will then sound an alert and can also pre-charge the brakes to provide braking force if deemed necessary. This system works in certain Japanese cities and requires Japan specific road markings that are detected by a camera.
  2009: Crown added a front-side millimeter-wave radar to detect potential side collisions primarily at intersections or when another vehicle crosses the center line. The latest version tilts the rear seat upward, placing the passenger in a more ideal crash position if it detects a front or rear impact.
  2012: Higher Speed APCS on the Lexus LS enables deceleration from up to 37 mph (60 km/h), compared to the previous of 25 mph (40 km/h). The higher speed APCS uses the same technologies as then current APCS. This system increases the braking force up to twice that applied by average drivers. It was not then available in U.S. markets.
  2013: Pre-collision system with pedestrian-avoidance steer assist and steering bypass assist can help prevent collisions in cases where automatic braking alone is not sufficient, such as when the vehicle is travelling too fast or a pedestrian suddenly steps into the vehicle’s path. An on-board sensor detects pedestrians and issues a visual alert on the dashboard immediately in front of the driver if the system determines that there is a risk of collision. If the likelihood of a collisi
caption: 2008 LS 600h forward PCS diagram, with radar (blue) and stereo camera (red) coverage
exif: {}