BERU f1systems' InfraRed Tyre Temperature Measurement System (IRTPTMS)
is a next generation tyre temperature monitoring system, with all the functionality of the current
legacy system, but now includes an infrared element in the wheel sensor which looks at the inside of the tyre's carcass and is able to accurately measure its temperature.
After two years of development with new processor and sensor technology we
are now able to offer the ultimate in tyre temperature performance
monitoring directly at the internal footprint and side walls if required.
The sensor mounted in the wheel is therefore able to wirelessly transmit data on the tyre's pressure, the sensor body temperature and the temperature of tyre's inner carcass.
The wheel electronic contains two lithium cells, a new generation integrated
absolute pressure sensor, temperature sensor, accelerometer, micro
controller and radio transmitter, plus an LF receiver and the IR sensor
element. All of this is housed in a custom enclosure designed to fit the
wheel rim it will be used on.
IRTPTMS Race vs. IRTPTMS Development
Whilst the IRTPTMS has obvious benefits for the motorsport industry, it is also very useful for development teams and tyre manufacturers who are keen to acquire a better understanding of their tyres’ behaviour. The requirements for these two groups of customers are quite different, and BERU f1systems have produced two systems to cater for these needs; IRTPTMS Race and IRTPTMS Development.
ECU
The IRTPTMS Development ECU retains the majority of the functionality of IRTPTMS Race, but houses the ECU in a plastic housing instead of a carbon fibre case. Similarly, the motorsport connector (8STA21035PN) is replaced with an AMP 32 way MQS connector. The combination of carbon fibre case and motorsport connector mean the Race ECU is sealed with an IP65 rating, whereas the Development ECU is classed with IP50 rating. Both ECUs provide a data stream on a high speed CAN bus, the speed of which is configurable via the PC software. Both ECUs are configured via a RS232 connection, using BERU f1systems’ IRTPTMS DigiTyreTM PC software. The software allows the user to specify warning limits, configure the CAN messages transmitted and also operates as a self contained data logger.
Wheel Sensor
To obtain the best possible tyre carcass temperature measurement, the IR sensor needs to view the tyre carcass at an angle less than 45° perpendicular to the area of the tyre carcass the sensor is taking the reading from. Where rim and tyre design allows, a custom housing can be created to mount the sensor so it can view the tyre carcass as close to perpendicular as possible. Figure 1 provides an illustration of how a custom designed housing can be mounted in the wheel/tyre assembled.
In cases where the rim and tyre design does not allow a sensor to be mounted in the centre of the rim, a valve mounted IRTPTMS sensor can be used. With this sensor, CAD models of the rim and tyre must be supplied to BERU f1systems to allow them to model the sensor on the rim, and determine the angle which the InfraRed element must be at, to view the required part of the tyre carcass.
The IRTPTMS wheel sensor is available with either a ±45° viewing angle, or a ±17.5° viewing angle. It is also available with a pressure measurement range of 0.882 - 4.6305bar, or 0 - 6.375bar absolute, depending on the required resolution. When the wheel sensor is stationary it does not transmit any information, which helps to preserve battery life. The internal accelerometer detects when the sensor is rotating at a speed greater than 30kph and the sensor then transmits at a rate of 1Hz. Should the sensor experience a change of pressure greater than 200mbar in one minute, regardless of the operational mode it is in, it will transmit 255 datagrams at a rate of 1Hz.
Antenna
The IRTPTMS Race Size 2 Antenna is housed in a very compact, high strength nylon housing, designed to allow the antenna to be mounted in the harshest of environments. The antenna uses a Size 2 Souriau connector to minimise weight, and keep the antenna as small as possible.
This antenna is also available as a populated PCB to allow teams to fit it into the smallest of spaces. Its light weight (12.5g) also means that the antenna can be positioned higher up in the car.
The IRTPTMS Development antenna uses a plastic housing, and a Size 6 Souriau connector. This antenna is designed to be mounted in locations which offer the antenna greater levels of protection.
IRTPTMS Race
Race ECU
ECU main features:
- High strength carbon fibre housing
- Waterproof and dustproof housing (IP65 rating)
- Motorsport connector
- LED status indicators on faceplate
- ECU configuration over RS232 connection
- CAN data output (baud rate configurable)
- Maximum operating temperature 85°C
- Weight – 100g
IRTPTMS Race Antenna – Size 2
Antenna main features:
- High strength nylon housing
- Waterproof and dustproof housing (IP65 rating)
- Motorsport Size 2 connector
- Suitable for mounting in high vibration, exposed locations
- Weight - 44g
IRTPTMS Race Antenna – PCB
PCB
Antenna main features:
- Very low profile, allowing mounting in the smallest of locations
- Solder pads on PCB to allow customer to wire straight to antenna
- Suitable for mounting in customer housing, or onto bodywork / chassis
- Weight - 12.5g
IRTPTMS Development
Development ECU
ECU main features:
- Plastic housing
- Splash proof case (IP50 rating)
- OEM grade connector
- Serial data stream available over HS CAN (baud rate configurable)
- Maximum operating temperature 80°C
- Weight – 75g
IRTPTMS Development Antenna Size 6 Connector
Antenna main features:
- OEM grade plastic housing
- Waterproof and dustproof housing (IP65 rating)
- Motorsport Size 6 connector
- Suitable for mounting in protected locations
- Weight - 48g
IRTPTMS Development Antenna Size 6 Connector
Antenna main features:
- OEM grade plastic housing
- Waterproof and dustproof housing (IP65 rating)
- AMP OEM grade connector
- Suitable for mounting in protected locations
- Weight - 48g
IRTPTMS Digital Display
The IRTPTMS display from BERU f1systems offers the driver a wealth of information, in a large easy to see format. The display has a number of screens, displaying different information for the driver. The screens can be scrolled through via push buttons which can be mounted anywhere in the cockpit. The main screen on the display provides information on the temperature and pressure of each tyre. Further screens are available by pressing a button, and display the following information:
- Tyre carcass temperature, plus ambient air temperature
- Individual wheel data. Including pressure, temperature, compensated pressure, wheel sensor ID, wheel sensor mode, remaining battery life
- Number of received datagrams from each wheel sensor
- Diagnostic information on the TPMS