Open Cut » Health and Safety
A suite of new collision avoidance systems (CAS) is presented for use in heavy vehicles whose structure and size necessarily impede driver visibility is introduced. The main goal of the project was to determine the appropriate use of each of the commercially available technologies and, where possible, produce a low cost variant suitable for use in proximity detection on large mining industry haul trucks. CAS variants produced were subjected to a field demonstration and, linked to the output from the earlier CAS 1 project, (a production high-definition in-cabin video monitor and r/f tagging system).
The CAS 2 system used low cost Doppler continuous wave radar antennae coupled to the CAS 1 monitor to indicate the presence of an object moving at any speed above 3 Km/h relative to the antennae.
The novelty of the CAS 3 system lies in the design of 3 interconnected, modules. The modules are 8 radar antennae (as used in CAS 2) modules located on the truck, software to interface with the end user (i.e. the drivers of the trucks) and a display unit. Modularisation enables the components to be independently tested, evaluated and replaced when in use.
CAS 4 expanded on the research in CAS 3 the Doppler radar antennae functionality was increased to allow object detection discrimination. This reduced the high bandwidth required by and essentially only informed the driver when an object was detected.
The radar antennae modules and the system as a whole are described together with the empirical tests conducted and results obtained. The tests, drawing on Monte-Carlo simulation techniques, demonstrate both the ‘correctness’ of the implementations and the effectiveness of the system. The results of the testing of the final prototype unit were highly successful both as a computer simulation level and in practical tests on light vehicles. A number of points are reviewed and their application to future projects discussed.
Chapter 9 reports on CAS 4 with the new microcontroller based fast Fourier transforms of the returned Doppler signals to give multiple object detection, speed and distance. A prototype of this system was installed on a Caterpillar 737D haul truck at the BMA Goonyella mine and tested for object detection and general robustness of the CAS 4 system.