User's Manual

BERU Electronics GmbH page 1
3 HL_10000 System and functional description
3.1 SR_10001010 - System description
The third generation system consists of just 5 components. It meets current EMC and radio guidelines
as well as legislative requirements (especially NHTSA FMVSS 138).
The compact control unit has an integrated receiving antenna. The RF receiving properties are
designed to ensure axle detection is possible for a wide range of vehicles by means of evaluating the
reception level.
The wheel electronic units belonging to the system use a high-integrated sensor (HIS) with pressure
and temperature measurement, 2-axle acceleration measurement, LF receiver, RF transmitter, power
management, and integrated µC.
The primary function of the system is monitoring tire inflation pressure while the vehicle is in operation.
The most important additional function of the system is the capability of detecting the wheels installed
on the vehicle (own wheels) and their installation location automatically.
The compact control unit is installed at a non-centralized location in reference to the vehicle axles.
The reception level of the RE is rated statistically to detect the mounting location of the wheel
electronic unit. This process determines the average value of the received field intensity of the
individual RE. After a certain number of telegrams, the system checks which wheels were received at
higher (average) reception levels and which were received at lower reception levels. The higher
reception levels were received from the REs which are installed closer to the receiving antenna. This
makes it possible to allocate wheel electronic units for the front or rear axle.
Direction of rotation is detected within the wheel electronic unit itself. The RE contains a 2-axle
acceleration sensor that measures radial and tangential acceleration, from which it derives the
direction of rotation.
3.2 SR_10003010 - Functional requirements for TSS system
Gen3
Following are the most important functional requirements for the third generation system:
• Pressure/temperature in the wheel
• Rapid availability of pressure warning information, self diagnostics, and wheel management
• Automatic own wheel detection, typically within the first minute after the startup process
• Independent axle detection by evaluating average levels
• Independent wheel position allocation, typically within the first minute of driving at > 30km/h
after the startup process in normal road traffic and pavement surface
• Independent wheel position allocation within the first 12 min of driving at > 30km/h after the
startup process
• Calibration of tire pressures
• Probe calibration (via bus command)
• US warning algorithm
• Connection to the vehicle bus via CAN bus
• Fast and reliable diagnostics of components
• Flashing in Customer Service
• Reliable process for simple mounting of wheel electronic unit
• Diagnostics via CAN