Automotive Safety Evolution

Prepared by Radovan Miucic

Copyright 2015 by Radovan Miucic Passive Safety • Seat Belts – 1885 first patent issued – 1951 three point seat belt – 1965 all 49 (except New Hampshire) states require by law – 1975 most of the developed world adopts – 1983 14% usage rate – 2008 83% usage rate – 1975-2008 saved 255,115 lives

Copyright 2015 by Radovan Miucic Passive Safety … cont. • Air Bags – Restraint system: inflates upon impact – 1950s designed – 1970s started in the US – 1995-2008 saved 27,000 lives – Air bags and seat belt reduce fatality risk by 61%

Copyright 2015 by Radovan Miucic Active Safety: ABS • Antilock Braking Systems (ABS) – ABS prevents wheels from ceasing to rotate during heavy braking – Helps driver control steering during braking – Prevents skidding – Helps wheels maintain traction to the surface – Electronic Control Unit (ECU) • 4 wheel speed sensor and hydraulic valves • ECU monitors wheel speed for a sign that wheel is rotating significantly slower than the others (wheel lock) • Valves are actuated to reduce the pressure at the affected wheel • ABS also works to slow down any wheel that is rotating too fast

Copyright 2015 by Radovan Miucic Active Safety: ESC • Electronic Stability Control (ESC) – Electronically minimize skidding – Detects loss of steering control • Applies on individual wheels • Helps steer the vehicle where the driver intends to go – Can reduce 1/3 accidents – Reduces rollover risks by 84% – From 2012 all new vehicles sold in the US are mandated to have ESC

Without ESC vehicle front With ESC, driver steering wheels move outwards correction through brake intervention mainly at the inner rear wheel.

Copyright 2015 by Radovan Miucic Brake Assist System: BAS • %90 of the driver failed to apply sufficient force during emergency • Initial BAS implementation was measuring the speed at witch brake pedal is pressed (panic brake condition) and then automatically boost braking • Later radar was used to detect emergency – Collision With Auto Braking (CWAB) • Nowadays BAS is integrated with Adaptive Cruise Control (ACC)

Copyright 2015 by Radovan Miucic Advanced Driver Assistance Systems • ADAS: Adaptive Cruise Cont., Blind Spot Assist, Attention Assist, Precrash Sys. • Uses sensors and actuators to assist the driver or take autonomous actions • Sensors: – Radars, cameras, wheel speed, temperature, etc. • Actuators: – Brakes, audio/visual warnings, haptic seats/steering wheel etc.

• Adaptive Cruise Control (ACC) – Maintains the speed set by the driver (like CC) if no obstacle ahead – Uses forward sensing radar (or laser scanner) to detect the speed and the distance of the vehicle ahead – Automatically adjust vehicle speed – Driver specify a following distance – Full or partial speed range Copyright 2015 by Radovan Miucic Blind Spot Assist

• 2005 commercially available • Side mirrors -> sensor based • Audio/visual warning, haptic seat or steering wheel • Some may include limiter steering control

Copyright 2015 by Radovan Miucic Attention Assist • Drowsiness cause 16% of the accidents • Implementation 1: Cameras monitor lane drifting patterns • Implementation 2: Cameras detects if the driver is becoming sleepy by monitoring eyelids • Implementation 3: sensors monitor steering patterns, braking, acceleration, weather, and road condition. • Issues audio and visual warnings

Copyright 2015 by Radovan Miucic Precrash Systems • Activated immediately before a crash • Use sensors to detect front or rear unavoidable collision • Potential Actions (within 2 seconds to impact): – Precharge brakes (to max braking force) – Inflate seats for extra protection – Move seats into upright position – Roll up windows – Tension seat belts, etc