# Brake Torque Sensor Calibration Device
## 2 Brake System
### Types of Brake Systems  
Two basic types of brake systems are used in today's cars, which differ in their construction and have their own advantages and disadvantages:  
1. Drum brakes--use drum-shaped housing where the brake shoes are pressed against the inner surface to create friction. They are durable and cost-effective for rear wheels. 2. Disc brakes--use a disc-shaped rotor that rotates with the wheel and the brake pads press against it to brake. Due to better heat dissipation and stopping power, they are usually used in front-wheel and high-performance vehicles. The advantages and disadvantages of this solution are introduced in Table 1.  
Another criterion for the division of brake systems involves the method of their control. According to this criterion, brake systems are divided into conventional brake systems and electronic brake systems. Conventional braking systems are controlled by the driver's power, while the driver not only determines the magnitude of the braking pressure with his foot but also the magnitude of the braking moments on the wheels of the car. The force of the driver creates hydraulic pressure in the master brake cylinder, which is transmitted to the wheel brakes with the help of brake fluid. In most light commercial vehicles and passenger cars, this hydraulic pressure is increased by means of a brake booster. The basic essence of generating braking force in electronic braking systems is based on the same principle as in conventional braking systems. The difference lies in the so-called \"intelligent braking\", where the braking effect is achieved through hydraulic and electronic parts of the system [35]. The use of intelligent braking and electronic safety elements using the brake system leads to much more frequent braking and, thus, longer periods of contact between the lining and the friction surface of the brake disc compared to conventional braking. The result is greater wear of the friction material. Therefore, the development is directed toward the optimization of brake systems and their parts, as well as the increase in energy recuperation [37; 38; 39]. The most common types of brake systems used in passenger cars are direct-acting fluid brakes. These brakes are based on [PERSON]'s law, which refers to the uniform spread of pressure in liquids in all possible directions. The rule applies that pressure in a liquid propagates at the speed of sound. With this rule, the braking start-up time and the braking distance itself will be shortened. An important property of \begin{table}
\begin{tabular}{l l l} \hline \hline
**Aspect** & **Drum Brakes** & **Disc Brakes** \\ \hline Design & Enclosed design with brake shoes & Open design with brake pads \\  & inside a drum & gripping a rotor \\  & Less efficient heat dissipation & More efficient heat dissipation \\  & Limited cooling due to enclosed & Better cooling due to open design \\  & design & Less susceptible to brake fade \\  & Strongly longer stopping & Shorter stopping distances \\  & distances & Require periodic adjustments for & Require less maintenance and \\  & optimal performance & adjustments \\  & & Can produce more noise during \\  & & braking \\  & & \\ Corrosion & Generally less susceptible to & More susceptible to corrosion in \\  & corrosion & rotor and caliper \\  & & \\ Brake dust & Generate less brake dust & Generate more brake dust \\  & & Simpler design with fewer & More complex with caliper, \\  & components & pistons, and rotors \\  & Typically more affordable & Generally more expensive \\  & Integrated parking brake & Parking brake functionality may \\  & mechanism & vary \\  & Weight & Heavier compared to disc brakes & Lighter compared to drum brakes \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The advantages and disadvantages of drum brakes and disc brakes [36]. the working fluid is its incompressibility at normal pressures in the system. Equalizing and distribution devices, which are necessary for mechanical brakes, can be replaced with working fluid.