Chapter 7 Maintaining Vehicle Stability Flashcards
Explain vehicle stability?
A vehicles stability is reduced when you break, accelerate or steer because these actions produce forces that alter the vehicles weight, distribution and balance and reduce tyre grip. A vehicle may skid when one or more of the tyres loses normal grip on the road.
What is a anti- lock braking system?
This is an electronic safety devise that adds to the conventional hydraulic braking system by giving you some ability to steer during harsh or emergency braking. ABS senses when a wheel is slowing down and about to lock up and then releases the brake on that wheel before it locks up fully. It then reapplies the brake once the wheel starts to rotate again.
What is emergency brake assist?
EBA increases brake pressure in an emergency situation. If you apply the brake with speed and force, EBA will cut in and fully apply the brakes until the ABS takes over to prevent the wheels locking up.
What is a traction control system?
When you accelerate, it’s possible for the power transmitted to the driving wheels to exceed the amount of available grip. The may cause the driven wheels to spin. TCS works by controlling excess wheel spin on individual wheels. It applies independent braking to the spinning wheel.
What is the Electronic stability programme?
An ESp is an active safety system which incorporates conventional anti lock braking and traction control systems. It’s designed to help vehicle stability by detecting when the vehicle is driven to the limit of it’s physical capabilities.
How does ESP work?
Sensors on each wheel work in combination with a sensor that monitors the rotation and pitch of the vehicle- called a yaw sensor. Another sensor on the steering assembly detects the driver’s intended path. If these sensors detect that th vehicle isn’t following the intended path, the system intervenes. It applies the brakes to individual wheels to correct understeer or oversteer and realign the vehicle.
How would you steer when using ESP?
It’s important that you steer in the direction you want to go
How does a skid happen?
A skid develops when one tyre or more loses normal grip on the road, causing an involuntary movement of the vehicle.
How to minimise the risk of skidding?
- check your vehicle
- observe- weather and road conditions
- anticipate and plan: adjust your driving to the road conditions
What are the common causes of skidding?
- driving too fast for the circumstances
- harsh acceleration
- excessive or sudden braking
- coarse steering
What is the difference between understeer and oversteer?
Understeer is the tendency of a vehicle to turn less and oversteer is the tendency of a vehicle to turn more.
What is understeer?
Understeer is when the vehicle runs wide of it’s intended course
What is oversteer?
Oversteer is when the rear of the vehicle steps out
What is aquaplaning?
Aquaplaning occurs where a wedge of water builds up between the front tyres and the road surface, often because of thin or worn tyre tread. Wider tyres are more likely to aquaplane. The safest solution is to remove pressure from the accelerator, although lownh the vehicle to lose speed and the tyres to regain grip.
