Appointment
The downhill aid system is one of the functions of the exchange stability system and is assigned to the active safety of the car. It is necessary to control the speed of a car that is going "under the hill." Most often, this system is installed on off-road vehicles-mainly 4x4 SUVs and crossover vehicles. It makes it much easier to ride mountainous and cross-terrain, and also improves security.
For this system there is no universally accepted three-letter designation-all producers refer to it differently. For example, in cars BMW and Volkswagen it is called HDC-"Hill Descent Control", it is called DACs-"Downhill Drive Support" in "Toyota", and "Nissan" has a slightly different-DDDS-"Downhill Drive Support".
In addition to help with descent, there is a system of recovery assistance with similar operating principles.
Device and operating principles
Since the system of assistance at descent is one of the functions of the exchange stability system, the principle of work of these systems is similar. Moreover, "descent aid" uses all the same design elements that apply to exchange rate stability.
So, a car equipped with this system can maintain a constant speed when descending automatically-it is done by the wheel-carrying of the wheels. Activates its button on the dashboard: however, a number of conditions must be met for the system to "come to help". First, the car must be built. Secondly, the driver shall not use the brake pedal or the gas pedal. Third, the descent should be more than 20%, at the speed of overcoming it-20 km/h.
The principle of work, as mentioned above, is working on the principle of exchange rate stability. The vehicle is equipped with sensors that signal to the control unit. Based on the data received, the robot includes the inverse pump as well as the intake valves and high pressure valves. However, the switching valves shall remain closed. As a result, the brake system is pressured to reduce speed to the required speed, depending on the gear engaged and the original vehicle speed.
When the speed reaches a certain value, the braking system is deactivated. The operation of the system of assistance in descending cycle-if the car has not yet reached the base of the mountain, the system is restarted-and so happens until it is turned off by a second pressing button, or until it is automatically turned off. This occurs when the driver presses the gas or brake pedal or when the gradient is less than 12 per cent.
