BRAKING

The automobile brake system is the most important in vehicles. In addition, it is an essential element to measure the performance of an automobile that affects the other properties of the vehicles. It is a mechanical device that inhibits motion by absorbing energy from a moving system to slow down or to stop a moving vehicle, most often accomplished by means of friction to convert the kinetic energy into heat. The brakes may be disc or drum type and the front ones play a greater part in stopping the car than the rear ones, because braking throws the car weight forward on to the front wheels. The disc brake has a disc that turns with the wheel and when the brake is applied, fluid pressure forces the pads against the disc. The drum brake has a hollow drum that turns with the wheel and a stationary backplate on which there are two curved shoes carrying friction linings covers its open back. Many cars have power assistance to reduce the effort needed to apply the brakes and the source of that power is the pressure difference between the partial vacuum in the inlet manifold and the outside air. Apart from the hydraulic braking system, all vehicles have a mechanical handbrake acting on two wheels, usually the rear ones. In critical driving situations (on a wet or slippery road), or if the driver is startled or shocked, the wheels can become locked when braking and this makes it impossible to steer the vehicle; the Anti-lock Braking System (ABS) detects incipient locking of one or more wheels at an early stage and selectively reduces the braking pressure. This ensures that the driver can avoid obstructions even with full braking and can brake the vehicle and bring it to a stop safely and quickly. Other systems that operate in conjunction with ABS are Anti-Slip Regulation (ASR) known also as Traction Control System (TCS) and Electronic Brakeforce Distribution (EBD). The ASR is designed to prevent the drive wheels slippage at all driving speeds and to reduce the wear and tear of the tyres and the EBD, always coupled with ABS, can apply more or less braking pressure to each wheel in order to maximize stopping power whilst maintaining vehicular control. For the braking field, De Lorenzo has designed two panels to simulate the behavior, with the help of a CAI software, such as to study the techniques and the electromechanical components used in hydraulic braking and in ABS systems. Troubleshooting’s are provided in both simulators. Two demonstrators are also available for this category. One basic allowing to work on ABS and ASR systems with the help of a microprocessor controller and another advanced trainer based on a Volkswagen Passat ABS/EBD/ASR system to show the structure and its operation. The latter demonstrator is equipped with intelligent faults setting and troubleshooting. All the trainers are recommended for professional institutes, vocational schools and technical colleges.