Positive results for new ABD path following steering robot

Industrial Robot

ISSN: 0143-991x

Article publication date: 1 June 2004




(2004), "Positive results for new ABD path following steering robot", Industrial Robot, Vol. 31 No. 3. https://doi.org/10.1108/ir.2004.04931caf.004



Emerald Group Publishing Limited

Copyright © 2004, Emerald Group Publishing Limited

Positive results for new ABD path following steering robot

Positive results for new ABD path following steering robot

Keywords: Robots, Automotive, Safety

Anthony Best Dynamics (ABD) of Wiltshire in England has reinforced the company's lead in the worldwide steering robot market with the development of a new path following system that allows a steering robot to control a vehicle along a specified path. The new path following robot enables meaningful real-life manoeuvres, which are very relevant to accident avoidance and traffic safety, to be investigated in a repeatable manner. In trials, the system has proved capable of controlling a vehicle during transient manoeuvres at highway speeds and at high lateral accelerations. The accuracy and repeatability of the path following robot far exceeds that of human drivers (Plate 4).

Plate 4

ABD steering robots provide a defined input to the vehicle's steering wheel to accurately assess the vehicle response and the course it takes depending on the dynamic characteristics of the vehicle. The use of a robotic system and precise computer control allows the units to provide accurate and repeatable inputs to the vehicle's steering system. In the past, these tests have been performed manually which has always made reliable data difficult and time-consuming to obtain. In contrast, ABD steering robots enable a wide range of test profiles to be played out to the vehicle's steering system with very precise control, making direct comparisons between vehicles easy.

Typically, when steering robots are used, the driver sits in the vehicle and controls the pedals and gear change whilst the robot controls the steering. Clearly, this requires the driver to have absolute confidence in the robot and it is essential that it is both safe and reliable. In these tests, the robot is typically programmed to provide a specified input to the vehicle's steering column, such as a step or sinusoid, and the response of the vehicle is measured. Although operators quickly learn to use the robot, testing without a path following system always requires concentration from the operator and a suitably spacious test area, because the path the vehicle will follow as a result of the steering input, is not known in advance of the test.

At present, by employing ABD's new path following option and the company's Omni controller, the steering robot is capable of driving a vehicle along a path representing a typical lane change or obstacle avoidance manoeuvre, at high speeds and approaching the limit of grip of the tyres.

A key part of the path following system is a transducer that can measure the position of the vehicle, real-time, and to a high accuracy. This transducer uses an inertial motion pack containing accelerometers and gyros which is corrected for drift using a differential GPS receiver and a mathematical algorithm. The system gives up to 2 cm position accuracy with a 100 Hz update rate, enabling it to be used as the feedback signal for the real-time controller.

The path following robot is programmed using a portable PC running a Windows NT based software package. The software enables a database of vehicles and tests to be built up with great flexibility in the test specifications. A range of sinusoidal tests are provided as standard; single period, continuous and swept sine, as well as step and pulse inputs.

ABD steering robots ensure that accurate and repeatable inputs are generated, overcoming a problem inherent in traditional manual testing methods, making it easy to obtain meaningful comparisons between different vehicles and vehicle configurations.

For more information, contact: Tony Best, Anthony Best Dynamics, Holt Road, Bradford on Avon, Wilts BA15 1AJ, England. Tel: +44 1225 867 575; Fax: +44 1225 864 912; Web site: www.abd.uk.com

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