Instrumentation Monthly Test | Measurement | Control
Gill Sensors, a UK design and manufacturer of non-contact sensor solutions, have expanded their application of position sensors by installing the Blade25 inductive position sensor into accelerator pedal assemblies. The Sensors have been fitted on a number of ride-on cleaning vehicles of a major UK manufacturer of domestic and industrial cleaning equipment.
The Blade25 position sensors have been installed on the ride-on scrubber dryers to provide excellent reliability and highly accurate positional measurement of the vehicles pedals during operation. The sensors had to be capable of relaying the real time position of the machine’s accelerator pedal and be extremely reliable due to the critical nature of the component. A non-contact solution was necessary, which would last throughout the lifetime of the equipment with no need to replace worn-out parts. In addition, exposure to dust and grit during operation and regular jet-washing in maintenance required the product to be fully sealed.
With both a linear measurement zone up to 25mm and angular measurements across 90 degrees, Blade25 easily covers the pedal movement range, proving to be the best fit for the vehicles layout, space and measurement requirements. Mounted to the pedal base assembly, Blade25 measures the position of a metallic target activator formed into the pedal. The activator passes over a series of coils mounted within the sensor. By alternately generating magnetic pulses in the coils and measuring differences in response from the activator, its position can be accurately determined.
One challenge that had to be addressed was the sensors detecting the pedal itself, which was manufactured as a single pressed piece of mild steel. This problem was most evident when the pedal was against its open and closed bump stops, and was easily resolved by setting constant voltages beyond the upper and lower limits of the measurement range. These could be interpreted by the controller as ‘full on’ and ‘full off’ values. This had the added benefit of total inter-changeability between pedal assemblies, allowing the sensors to be standardised for production use.
With the calibration finalised, Gill was supplied with a serial data string for pre-loading into the sensors prior to despatch removing any need for assembly line calibration. In addition, the Blade25 standard cable was also customised for digital output, offering a wiring harness integrating a RS-232 connector to allow seamless integration into the machine’s existing control unit. The adapted Blade25 sensors were then truly ‘plug and play’ and could to be built to order as need dictated.
Gill Sensors is a well-known brand in the automotive industry and has an established reputation for providing high quality position sensors across a broad range of applications including test laboratories for pedal, suspension and pneumatics applications.
A video of the application is available from the Gill Sensors YouTube channel http://www.youtube.com/watch?v=97OML4un6yo&feature=c4-overview-vl&list=PL3D1192AC1FFB36DF
www.gillsensors.co.uk/position
01590 613400.