Tuesday, July 3, 2012

Star Safety System - Part Two

It's been a while since I did part one, but now I'm going to cover part two which will include Vehicle Stability Control (VSC), Brake Assist (BA), Electronic Brake Force Distribution (EBD) and Smart Stop Technology.  

Vehicle Stability Control 

Vehicle stability control is essentially traction control for when the vehicle is in motion.  The program is designed to keep the vehicle on it's intended path.  It does so through a complex set of sensors that measure steering input, vehicle speed, individual wheel speed sensors, throttle input and yaw sensors.  It is not a substitute for safe driving, but it can help a great deal in emergency situations when a driver has to make evasive actions.

The system will reduce throttle input even if you put the pedal to the floor if it senses a loss of control or traction.  This system can greatly reduce the risk of rollovers in SUV and trucks that have a high center of gravity.  The government did studies that show that 41% of single vehicle accidents could have been avoided if all vehicles were equipped with this system.  This led to the mandate that all vehicles 2012 model year and newer are required to have a stability control program as standard equipment.  The system has been standard on all Toyota SUV's since 2004.

Here's a video clip of a 2013 Scion FR-S on a wet slalom course with the system turned on (default mode), then in Sport VSC mode (most cars don't have this mode) and then finally with all the systems turned off.  As you will see, the program helps a ton on maintaining control of the vehicle.

If you want to read in more detail about this program, you can do so here on Wikipedia

Brake Assist

Brake assist is another program designed to increase the safety of new vehicles.  The program will detect a "panic" braking situation and apply maximum braking force.  It will do this by the speed the brake pedal is depressed.  Studies have shown that drivers may not always be able to apply maximum braking pressure on the pedal due to seating position, physical ability and other reasons.  Brake assist has been shown to reduce stopping distances by a significant margin, up to 20% in some studies.  

Brake assist doesn't interfere with normal driving situations and you will most likely not even notice it working when it engages.  If you quickly stab on the brake pedal like you are going to "panic" stop and then let up on the brake pedal, then you may notice that the vehicle still slows to a stop just like if you were standing on the brake pedal.

Electronic Brake Force Distribution

Electronic brake force distribution will vary the braking pressure applied to each individual wheel depending on the load of the vehicle, speed and road conditions.  Most of the time under normal conditions, the majority of the braking force is applied to the front wheels because that is where the majority of the load is on a vehicle.  

A truck is a great example to use.  Normally a truck is very biased as far as weight goes towards the front of the vehicle.  Now, put a load of mulch/cargo/etc into the bed of the truck and it's weight distribution is very different.  It will now have more weight towards the back of the vehicle than normal.  EBD will recognize this and transfer more braking pressure to the rear of the vehicle to get a more controlled and shorter stopping distance by applying braking force to each wheel individually. 

Smart Stop Technology

Smart Stop Technology was created by Toyota as a measure to prevent unintended acceleration.  This technology is a result of the recalls from 2009-2010.  The way the system works is that it will reduce engine power when both the brake and gas pedal are pushed at the same time under certain conditions.  Smart Stop will engage when the accelerator is pressed first and the brake is applied firmly for longer than one-half second at speeds greater than 5mph.  

In normal driving situations, you won't even notice this program.  If the brake pedal is pressed first, and then the accelerator, the system will not engage.  This is to prevent the system from engaging when you are starting out on a hill and want to prevent the vehicle from rolling backwards