The tests, which took place earlier this year, form part of the extensive Bloodhound SSC Project testing programme ahead of its 1,000mph land speed record attempt, which is scheduled to take place in South Africa next year. The ride-height tests were carried out at Jaguar Land Rover’s Gaydon Centre in Warwickshire, which accommodates the auto maker’s design and R&D facilities and test track.
“Measuring the ride height is a critical measurement parameter on the Bloodhound Supersonic Car,” says Joshua Thompson, a systems engineer on the Bloodhound Programme. “We need to know the exact distance between the wheels and the ground to see how far into the ground the wheels sink during trials.”
Mounted to the chassis of a Jaguar XF test vehicle with the laser window pointing down towards the ground, a Micro-Epsilon optoNCDT 1700 high speed laser displacement sensor is deployed to measure and monitor the ride height of the car with great accuracy.
While the sensor will enable the Bloodhound SSC team to adjust the suspension characteristics in order to optimise the performance of the car, the objectives of the ride height tests at Jaguar were twofold, as Joshua Thompson explains:
“First, we needed to test the performance of the ride height sensors under harsh, on-vehicle conditions. We also wanted to verify that our software could correctly interpret the measurement data coming from the sensors. On both counts, the tests were successful.”
For the ride height test set-up, two optoNCDT 1700 laser displacement sensors were mounted side-by-side on an adapted tow bar fixed to the rear of the Jaguar XF. “We wanted to compare the measurement data coming from the two sensors, which were set up at a measuring range of 300mm from the ground [the midrange of the sensor] to measure the ride height of the car,” Thompson adds. “In the record attempt itself, one ride height sensor will be mounted to each of the four wheels on the car.”
Flawless performance
During the tests, the car was accelerated to a maximum speed of 50mph, as the off-road conditions were too muddy and bumpy for higher speeds to be reached. However, as Joshua Thompson observes, the two optoNCDT 1700 sensors performed flawlessly during the tests. “They captured the data we required and there were no discrepancies between the two sensors in terms of the analogue output data they provided,” he reports.
The optoNCDT 1700 series of laser displacement sensors provides multi-functional features. The novel real time surface compensation (RTSC) feature enables measurement against a wide range of material surfaces. Moreover, its compact design (and integrated signal conditioning electronics) ensures easy installation in a variety of industrial applications, including R&D, testing, automation and OEM production systems.
Measuring ranges are from 2mm to 750mm; maximum linearity is 2µm and maximum resolution is 0.1µm. Measuring rates are configurable up to 2.5kHz and a freely programmable limit switch is also provided.
In addition to the ride height sensors, Micro-Epsilon is also providing sensors to the Bloodhound Programme that will be used throughout the testing, production and operational stages. These include non-contact temperature sensors, thermal imagers and non-contact capacitive displacement sensors.