Curtiss-Wright’s industrial division has more than 50 years experience in providing control and feedback systems for a variety of applications – including the aerospace sector - and is no newcomer to motorsport where customisation is generally the order of the day.
Curtiss-Wright’s sensors have been used in numerous race series including the American Le Mans Series (ALMS), Formula One (F1) and Formula Student, in applications ranging from active suspension control to position sensing using the latest Hall-effect position sensors. Indeed, the company claims to be among the first position sensor manufacturers to enter motorsport and has supplied every F1 championship winning team since 1986.
“With a performance to match today’s Formula racing cars, the single-seat Mono required an equivalent level of intuitive direct control, so BAC designers and engineers specified components that were themselves designed and engineered for the racetrack,” says Curtiss-Wright industrial division’s Kevin Rayment.
Mono is the vision of BAC design director Ian Briggs, who had motorsport very much in mind during its evolution. However, he also wanted the car to feel at home as much on country lanes as it does on the race track
“I wanted Mono to be high tech and totally fresh in its approach,” says Briggs. “A car for people who want to feel a connection, and be really involved in the character of the car they drive. It had to be a car people would be consistently excited by, and would experience pride in owning. In short, Mono is a totally immersive experience, from start to finish.”
Operated via steering wheel-mounted paddles, Mono uses an F3-specification, six-speed sequential Hewland gearbox with an electronic/pneumatic semi-automatic, closed-loop gear selection system that delivers paddle-shift changes in 35 milliseconds. This is coupled to a 2.3 litre, 285bhp four-cylinder Cosworth engine enabling the Mono to achieve a 0-60mph time of less than three seconds.
The closed-loop control system on Mono uses a gearbox control unit (GCU) with inputs from a Penny + Giles gear position sensor to alter its own operation in real-time. During gear changes, the closed-loop system monitors the gear position sensor to determine the angular position of the gearbox selector barrel. Featuring a special connector cable and a configured output range to match the specific shaft position, the contactless rotary position sensor installed on BAC’s Mono is a customised version of the standard Penny + Giles SRH280P model.
Gearbox selector barrel angular position information is subsequently relayed to the GCU to ensure use of the throttle blip, torque reduction or pneumatic actuator where necessary, to accomplish consistently quick and reliable gearshifts.
“Used to relay gear position feedback to the GCU, sensors were vital during BAC’s development of Mono and are as vital under normal and track day driving conditions in informing the driver of the car’s current gear. We therefore needed a sensor that was dependable, reliable and met our exacting requirements for Mono, so we called Penny + Giles,” adds BAC co-founder and technical director Neill Briggs,
Standard Penny + Giles SRH280P rotary position sensors use a factory-programmable, non-contact Hall-effect sensor system to provide reliable and accurate rotary position measurement in extreme motorsport and industrial environments subject to shock and vibration. Additional key features include single or dual output channels; a total sensor measurement range from 0-20° to 0-360°; low noise level (1mV rms) on output signal, and a crush-proof mounting flange with steel inserts.
Using the popular 38mm flanged housing and with an environmental protection rating to IP68, the sensors operate from either 5Vdc regulated or 9-30Vdc unregulated power supplies and are available with analogue (0.5 - 4.5Vdc and 0.1 - 4.9Vdc) or digital (PWM) output signals.
The sensor is factory programmable, allowing OEMs to specify the output signal type, measurement range (0-20° to 0-360° in 1° increments) and output direction (clockwise or anticlockwise). It has a 12 bit resolution (0.025 percent) over the selected measuring range, and operates from -40 to +140°C when powered at 5Vdc.