Jaguar Racing steps up a gear

A novel variable-speed-drive-based test rig is helping Jaguar Racing improve the design of the gearboxes for its Formula One team.

When success or failure is measured in hundredths of a second, the testing of every component of a Formula One car takes on increased significance.

And, when that team is Jaguar Racing, it's no surprise that the test facilities at their Milton Keynes centre use cutting edge technology.

An example of this is the company's 160kW variable-speed drive gearbox testing rig, which has been designed, programmed and installed by drives specialist Control Techniques.

Continuing investment in the development of the rig has seen the recent rethink of the complete 'front end' of the rig, which now features a Control Techniques Scada system to provide an enhanced level of performance analysis.

The function of the rig is to simulate the on-track conditions that gearboxes encounter during Formula One races, including overrun conditions experienced during rapid slowing, where the wheels (and therefore gearbox), drive the engine, requiring rapid reversing of the direction of torque.

The test rig comprises three 160kW motors, each driven by a Unidrive and a 5.5kW motor driven by an equivalent sized Unidrive.

One 160kW motor, driving at 4300rev/min through a step-up gearbox, runs in speed control to mimic the engine output, giving a maximum output through the Jaguar gearbox of 18,000rev/min.

The two other 160kW motors are in closed loop torque control and are coupled to the output shafts of the Jaguar gearbox to simulate the output loads.

The final 5.5kW Unidrive, referenced from the input drive, controls the gearbox oil pump motor.

System control is via Control Techniques' own high-speed network, CT-Net, that provides communications between the Unidrives' onboard UD70 SYPT-programmed application modules and the Pi-Sigma race car control system, as used on F1 cars.

SYPT is Control Techniques' own Windows-based graphical programming software.

The Pi-Sigma 'driver' control (complete with wheel and racing gear-change) sends speed reference signals to the input drive and independent torque control or load-sharing signals to the output drives, to simulate driving conditions.

Now, using Control Techniques' own Scada system, CT32, the Jaguar Racing test engineers are able to monitor and plot more than 40 variables including drive outputs, power, current, torque and speeds, time delays on gear-changing as well as oil temperature/flow/pressure and a number of alarm setpoints.

"The Scada system has improved our data-logging and trending as well as enabling us to check that every aspect of a test has been completed properly", says Test Engineer at Jaguar Racing, Rory Oliver Hall.

"It's very easy to understand and clear to read so there are no misunderstandings", he says.

CT32 is Control Techniques' own data visualisation tool.

Based on Intellution FIX32 technology, it is applicable for small to medium systems using Control Techniques drives and I/O running on CT-Net, as in this instance, ANSI or single drives on RS232.

The key features of this Scada system include process monitoring and control, data collection and display, historical trending, alarming, data archiving and many more features.

This gearbox testing rig is in regular use throughout the year, ensuring that three spare fully tested gearboxes are available for each race.

New gearboxes are subjected to rigorous tests in both forward and reverse over about 90min, whereas used gearboxes have a shorter test regime.

Tests start with a warm-up period under no load, which enables the test engineers to monitor the oil flow rates, temperature and pressure.

Then loading is progressively increased right up the speed range to around 16,000rev/min.

During this run-up period, the comprehensive facilities provided by the test rig enable the engineers to tune sensors in the gearbox and to calibrate clutch and gear positions using the Pi-Sigma control unit.

Because the Unidrives provide power regeneration during slow-down, the energy consumption of the rig is minimised.

In normal running, the power used from the mains is minimal as a result of the power on the DC bus recirculating.

This is achieved by the output drives putting power back into the common bus also used by the input drive.

Control Techniques has considerable experience in the provision of drives for test rigs for racing, mainstream automotive, truck and helicopter engines.

Back to top