Archive:Data acquisition system

DAS: Data Acquisition Systems.

Data logging, carried out by data acquisition systems known as DAS is used to measure many if not all parameters around performance race vehicles, storing the recorded data for analysis to improve and develop performance systems while also devise strategy for race events.

Data logging systems consist of four elements (see image):

Measuring output (sensors around the vehicle) Recording output signals (logger unit) Uploading\accessing recorded data (telemetry) Analysis of recorded data. (DAS software)

The four elements above have specific requirements which need to physically present and included in the design process. For instance the required sensors to measure selected parameters and the routing of the sensor cables ensuring they will not suffer from electromagnet interference from other electronic systems, the DAS unit including memory and the link from the DAS unit to the operating platform to upload the acquired data via a hardwire cable or telemetry.

Most race cars are using two types of telemetry, the first being sent to the engineers in the pits every time the vehicle passes (50mb of data), containing an insight into the state of the vehicle, and the second being transferred each time the vehicle is in the pit lane, both providing much needed information on every part of the vehicle. The most advanced telemetry include the data being sent constantly for analysis through a transmitter as long good connection is present (not always possible in parts of certain raceways due to obstruction).

The operating platform required is to include the specialist analysis software to view the data usually in the form of various graphs to improve and develop the performance of the key areas and operation parameters of the vehicles running conditions: the most advanced software in Formula 1 has been developed by Mclaran electronics known as Advanced telemetry Linked Acquisition System, which displays graphs of each of the vehicles systems on the exact section of track, in a real time format. The benefit of using such a system is phenomenal because the parameters in which can be recorded for analysis cover the whole set-up of the race vehicle (up-to 127 channels). The parameters which are measured and recorded by a data acquisition system are broken into three generic categories which are also interlinked due to system requirements and the complexity of major components which require several different parameters. This can be shown when looking at a wheel speed sensor, which not only monitors the wheel speed but also with other parameters the speed of the vehicle, location on the track and an input to traction and launch control systems.

Engine: Revs per minute, fuel and oil pressure, water and oil temperature, turbo charger boost pressure, exhaust gas temperature, battery voltage, inlet air temperature and throttle position sensor. Chassis: Wheel speed, steering angle, lateral and longitudinal G-force (applied from braking and cornering), Brake line pressure, damper movement and gearposition. Advanced Chassis DAS: Ride height, drive-shaft of prop-shaft torque, suspension loads, tyrepressure and compound temperature, brake disk temperature. Aerodynamic parameters which may be monitored include air speed and local air pressures. Driver: Both engine and chassis related which are controlled by the driver such as throttle position, gear position, steering angle and brake line pressure or directly controlled parameters such as engine revs per minute, speed and G-force.  The accurate information provided by telemetry sent by DAS in practice takes fine tuning to the extremes, such as ensuring the correct gear ratios are present according to track layout. Also the engine acceleration speed according to throttle position and sensitivity is set-up to the required conditions of that race. The engine control system will be programmed with suitable engine maps giving the driver more control of the throttle input making the first part of pedal movement very sensitive to negotiate a track with a large number or corners such as Monaco allowing the pilot to pull off the apex smoothly. Somewhere like Hockenheim however requires the vehicle to come out-of the chicanes and straight on the gas up-to peak power levels as soon as possible, thus less sensitivity required on the pedal.

The DAS during race time will be monitored by several workstations which engineers in the pit and garage area constantly monitor the vehicle diagnosing any faults which may occur, using the DAS as an early warning system of potential mechanical failure, allowing the designers and material analysis back at base to easily distinguish what caused the fault. The benefit of telemetry is incomparable to any other system, giving the whole race team the holy grail of data required to increase all aspects, while also decrease the danger levels of the sport to the driver:

A good example of this can be taken from the 2003 Silverstone GP, when engineers in the pits observed the loss of pressure from one of Coulthards tyres. The DAS allowed the team to recall him from his practice, resolving the fault before a dangerous situation occurred.

The DAS and telemetry system is that important within a team, acting as the digital backbone to control the most advanced hybrid mechanical systems that the set-up and detail of the system itself is just as important as the Formula one vehicle.

“Formula 1 telemetry is the technological lifeblood of the sport, helping the drivers and engineers to better understand how a car functions and how they can optimise its set-up.”

Mclaren Electronics.

Oliver Metcalfe