Indycar anti roll bar position sensors
Non-contact position sensors improve IndyCar handling performance
Gill Blade60 non-contact position sensor has been integrated into an anti-roll bar (ARB) lever assembly in a number of IndyCars to provide accurate real-time positional masurements. The ARB system has been developed for use in the American IndyCar series to address vehicle handling issues and improve race performance.
The 2013 open-wheeled championship consists of 19 high-speed and widely varied circuits, each designed with a complex combination of sharp turns, corners and bends, making car handling characteristics extremely important. Effective management of the cornering forces on the suspension is crucial to determine the success of a race.
Doug Shelby Engineering (DSE) took on the challenging task of developing a non-invasive ARB sensor fixture using Gill Blade60 non-contact position sensors, to track the position of the anti-roll bars during race use. Two Blade60 sensors have been installed in each lever assembly to provide accurate positional measurement of the mechanical linkages (anti-roll bars) attached to the front and rear suspension.
The application required a reliable and robust sensor, resistant to mechanical damage and the harsh environmental conditions experienced on the track. The previously used potentiometers and hall-effect sensors are potentially vulnerable to these conditions leaving them open to inaccurate and unreliable data reporting.
DSE chose the Blade60 non-contact position sensor to measure the position of the ARB levers. Blade60 sensors are solid-state and fully sealed, offering unlimited mechanical life and long-term reliability in harsh operating environments. Fitted to both sides of the ARB lever assembly, the inductive sensors provide the team with accurate real-time data, giving the driver and pit crew a true representation of real-time mechanical setup.
The ARB lever allows the driver to adjust the stiffness of the anti-roll bar to vary the mechanical roll of the vehicle and reduce adverse effects on the tyre camber caused by cornering forces. Correct adjustment of the lever means more of the tyre is in contact with the road, improving handling performance and reducing tyre wear.
The position readings provided by the sensors allow the driver to make adjustments at the precise moment required to effectively control the movement of the car. Data accuracy is crucial as an incorrect sensor reading can lead the driver and crew in the wrong direction when addressing handling issues.
“The driver must always know the positions of the roll bars as must the engineering crew back in the pits. A reliable sensor is required to monitor these levers and The Blade60 sensors were a cost-effective solution to all of the requirements” explains Doug Shelby. “The solution is also superior to the sensor technology it has replaced. Depending on the installation, string and linear potentiometer calibrations could vary car-to-car and leave an open possibility for inaccurate data. The digital circuit boards with hall-effect sensors are invasive to the assembly and must be individually customised for the specific ARB position gates. The Blade 60 has eliminated calibration variance and offers the resolution necessary to adapt to unlimited ARB gate changes.”
Currently Blade60 has been installed into the ARB lever system of 10 IndyCars and is also used to measure weight jacker position on one car. Gill capacitive liquid level sensors are also installed in a number of the cars of major teams, providing reliable and accurate fuel and oil level measurement.
A reliable and robust sensor, resistant to mechanical damage and harsh environmental conditions was required for the application