TSS 2. Generation Tire Safety System TSS 2nd. Generation Systembeschreibung TSS System description TSS Dokument Nr.:
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c freigegeben am /date of release 17/01/07 Systembeschreibung TSS System description TSS Titel:
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Dokument Nr.: 3530.001.002.00.27 Document no:
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c 00 Revision regarding RE G2.3 TSS 2. Generation Tire Safety System TSS 2nd. Generation Erstellt / Datum:
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Kninger 15/01/07 Birringer 16/01/07 Saric 17/01/07 Revision service Index:
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b a 00 00 Beschreibung:
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315MHz components included First version Saric 03/09/06 Saric/
8/26/05 Saric 03/09/06 Birringer/
8/26/05 Saric 03/09/06 Saric/
8/31/05 TSS 2. Generation Tire Safety System TSS 2nd. Generation Systembeschreibung TSS System description TSS Dokument Nr.:
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c freigegeben am /date of release 17/01/07 Section 15.19: Labelling requirements This device complies with Part15 of the FCC Rules. Operation is subject to the following two conditions:
(1)
(2) this device may not cause harmful interference, and this device must accept any interference received, including interference that may cause undesired operation. Section 15.21: Information to the user The user manual or instruction manual for an intentional or unintentional radiator shall caution the user that changes or modifications not expressly approved by the party responsible for compliance could void the users authority to operate the equipment. IC statement according to RSS210 5.11 User Manual Operation is subject to the following two conditions:
(1) this device may not cause interference, and
(2) this device must accept any interference, including interference that may cause undesired operation of the device TSS 2. Generation Tire Safety System TSS 2nd. Generation Systembeschreibung TSS System description TSS Dokument Nr.:
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c freigegeben am /date of release 17/01/07 Contents:
1 SYSTEM AND FUNCTIONAL DESCRIPTION ................................................................................................. 5 1.1 SYSTEM DESCRIPTION ................................................................................................................................................. 5 2 3 FUNCTIONAL DESCRIPTION ............................................................................................................................ 6 WARNING ALGORITHM ..................................................................................................................................... 8 3.1 WARNING LIMIT MINIMUM PRESSURE ..................................................................................................................... 8 3.2 WARNING LIMIT NOMINAL PRESSURE MINUS RELATIVE DEVIATION (NOMINAL PRESSURE X %) .......................... 8 4 SYSTEM COMPONENTS...................................................................................................................................... 8 4.1 4.1.1 4.1.2 4.1.3 4.1.4 4.1.5 4.1.6 4.1.7 4.1.8 CONTROL UNIT............................................................................................................................................................ 8 Installation area................................................................................................................................................. 9 Temperature range............................................................................................................................................. 9 Voltage Range.................................................................................................................................................... 9 Current consumption ......................................................................................................................................... 9 Occupancy of the CAN control unit:.................................................................................................................. 9 Occupancy of the K bus control unit: .............................................................................................................. 10 CAN bus connection......................................................................................................................................... 10 K bus connection.............................................................................................................................................. 10 4.2 WHEEL ELECTRONIC ................................................................................................................................................. 10 Installation area............................................................................................................................................... 11 4.2.1 Versions ........................................................................................................................................................... 11 4.2.2 Temperature..................................................................................................................................................... 11 4.2.3 Pressure ........................................................................................................................................................... 12 4.2.4 Service Life....................................................................................................................................................... 12 4.2.5 4.2.6 Environmental requirements............................................................................................................................ 12 4.2.7 Mechanical specification ................................................................................................................................. 13 4.2.8 Measurement specification .............................................................................................................................. 13 4.2.9 Specification for HF transmitter ...................................................................................................................... 13 Transmitting power .................................................................................................................................................. 14 4.2.10 Block diagram wheel electronics ..................................................................................................................... 14 DIGITAL ANTENNA.................................................................................................................................................... 15 Installation Area .............................................................................................................................................. 15 4.3.1 General Dimensions and Values...................................................................................................................... 15 4.3.2 Temperature ranges ......................................................................................................................................... 15 4.3.3 Voltage supply.................................................................................................................................................. 15 4.3.4 Current consumption ....................................................................................................................................... 15 4.3.5 Environmental conditions ................................................................................................................................ 15 4.3.6 TSS BUS communication with TSS control unit............................................................................................... 16 4.3.7 Connection occupancy, sleeve strip ................................................................................................................ 16 4.3.8 4.3.9 Block diagram.................................................................................................................................................. 16 4.3.10 Assembly .......................................................................................................................................................... 17 TRIGGER TRANSMITTERS .......................................................................................................................................... 18 4.4.1 Temperatur / temperature ................................................................................................................................ 18 4.4.2 Mechanische Anforderungen / mechanical requirements ................................................................................ 18 Voltage Range.................................................................................................................................................. 18 4.4.3 4.4.4 CurrentConsumption........................................................................................................................................ 18 4.3 4.4 TSS 2. Generation Tire Safety System TSS 2nd. Generation Systembeschreibung TSS System description TSS Dokument Nr.:
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c freigegeben am /date of release 17/01/07 4.4.5 Frequenz / frequency........................................................................................................................................ 18 4.4.6 Modulation / modulation.................................................................................................................................. 18 4.4.7 Physikalische Schnittstelle / physical link........................................................................................................ 19 Protokoll / protocol.......................................................................................................................................... 19 4.4.8 4.4.9 Diagnose / diagnosis........................................................................................................................................ 19 4.4.10 Stecker / connector........................................................................................................................................... 19 4.4.11 Environmental Qualification............................................................................................................................ 19 4.4.12 Schematic Representation of the Trigger Transmitters.................................................................................... 20 TSS 2. Generation Tire Safety System TSS 2nd. Generation Systembeschreibung TSS System description TSS Dokument Nr.:
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c freigegeben am /date of release 17/01/07 1 System and functional description 1.1 System description The Tire Safety System (TSS) controls and monitors tire pressures. The system comprises the following components:
1 TSS control unit 4 sets of wheel electronics including valve 1 digital antenna 4 trigger transmitters The wheel electronics mounted inside the tire measures tire pressure and temperature at regular intervals and transfers the values telemetrically via a HF transmission line to a reception antenna. The current pressure and temperature values can be requested specifically via the trigger function. In the receiver antenna, the radio data telegram is decoded and transferred to the control unit as a digital signal. The control unit evaluates the received data and forwards the information to the driver as required. This provides the driver with information on the necessary tire pressure or tire tension adjustments. The benefits offered by the tire pressure control system are:
Safety An early warning in case of fast pressure loss is given.
"Blow-outs" caused by excessive flexing and driving too fast on inadequate tire pressure are avoided. The driver is prompted to adjust the tire pressure where necessary. Comfort Tire handing is made simple. Using the filling equipment at the fuel station and removing the valve cap is only necessary for correcting the tire pressure. New tire developments Tires with limp-home features avoid having to change a wheel immediately and render the spare wheel superfluous. They do, however, require permanent monitoring of the tire pressure. Service life and economy Tire wear is minimized through correct air pressure. TSS 2. Generation Tire Safety System TSS 2nd. Generation Systembeschreibung TSS System description TSS 2 Functional description Dokument Nr.:
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c freigegeben am /date of release 17/01/07 to 175ms ensures that no periodic signal The wheel electronics are mounted within the tires and measure tire pressure, temperature and wheel electronics. The measured data is sent from the wheel via a transmitter in the wheel electronics. A system with relatively seldom measured data transfer is adequate for tire pressure monitoring provided it features the additional option of detecting sudden pressure loss. This enables the electronics in the wheel to be designed for minimum power draw and battery operation. All wheel electronics have their own code (ID) that is forwarded with the data at each transfer. The HF transfer occurs in the 433 MHz range or, referred to as the ISM range and/or in some countries in the 315 MHz range. The trigger functionality is achieved by a 125kHz LF channel. The control unit calls up the wheel electronics via the trigger transmitters every 54 s ( a random generator with a jitter of 25ms to send data messages. Tire pressure and wheel electronics temperature are also measured every 3 seconds. When a pressure loss
> 0.2 bar on the last sent pressure value is detected, the wheel electronics switch immediately to fast-send mode. In this situation, the wheel electronics measure and send every 0.8 seconds. The TSS measures and transfers considerably more data than is necessary to ensure reliable basic function. It can therefore use a data transfer path that is not assigned for the error-free transfer of each individual data protocol. Using the trigger function, an implausible and/or non-received data message can be requested again from the corresponding wheel electronics. The data sent by the wheel electronics is received via the digital antenna and is decoded. The decoded data is transferred onwards to the control unit via a digital interface. The control unit evaluates the received data and forwards the information to the driver information system as required. This provides the driver with information on the necessary tire pressure or tire tension adjustments. The main functional characteristics of the control unit are:
- A central warning algorithm and an algorithm for the wheel manager
The vehicle-specific connection for the power supply system and manufacturer-specific operation and display philosophy is generated) The essential feature of wheel management is the self-learning system with automatic individual wheel detection and the detection of the corresponding installed positions (wheel position detection). Thanks to fast triggering of the wheel electronics when Ignition is ON, the system detects a flat tire well before the start of a journey. TSS 2. Generation Tire Safety System TSS 2nd. Generation Systembeschreibung TSS System description TSS Dokument Nr.:
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c freigegeben am /date of release 17/01/07 CAN bus For Driver Information System TSS-bus TSS control unit CAN Interface TSS-Bus Interface Function software Antenna TSS-Bus Interface HF receiver Function software Trigger 1 WE 1 Trigger 2 WE 2 Trigger 3 WE 3 Trigger4 WE 4 Figure 1: Block diagram, TSS system of the second generation TSS 2. Generation Tire Safety System TSS 2nd. Generation Systembeschreibung TSS System description TSS Dokument Nr.:
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c freigegeben am /date of release 17/01/07 3 Warning algorithm The system monitors a nominal pressure, which is set by the operator, and a fixed set minimum warning pressure. The higher value in each case is used to generate the breakdown warning. The driver instructs the system to accept the current pressure values as the nominal pressure by using the Reset. The reset is triggered by pressing a key or selecting a menu item. 3.1 Warning limit Minimum pressure At this warning limit, a check is made against the minimum warning pressure PWarning_MinimumPressure, which is programmed into the system as a fixed value. The minimum warning pressure amounts to 2.6bar abs plus an accuracy reserve of 0.1bar. The corresponding warning bit is set, if the measured pressure lies below this threshold twice in succession. 3.2 Warning limit Nominal pressure minus relative deviation
(Nominal pressure x %) This warning limit is calculated from the nominal pressure less a relative deviation of 25% of the nominal pressure. The nominal pressure is specified by the driver. Again here an accuracy reserve of 0.1 bar is added to the warning limit. The corresponding warning bit is set, if the measured pressure lies below this threshold twice in succession. 4 System components The system components of the TSS system are described below 4.1 Control unit The control unit consists of a printed circuit board with microcontroller with interfaces for CAN- or K bus and TSS-Bus. The software is based on an OSEK Operation System. The tire information received from the digital antenna is recorded and evaluated in the control unit. The pressure information and, if applicable, the warning information, is forwarded via the CAN bus to the display systems in the vehicle. The information from the digital antenna is transferred to the control unit via a so-called TSS Bus communication. The control unit is the Bus master here, while the antenna or the trigger transmitters work as slaves. The control unit interrogates the digital antenna at set intervals with respect to radio messages. The trigger transmitters are contacted in sequence, in order to give them orders with respect to trigger commands that are to be carried out. The control unit also supplies the supply voltage to the trigger transmitters and the antenna. The most important details of the control unit are described below.