Control Engineering

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Truck Vision
April 28, 2008

Iteris 

DRIVER ASSISTANCE
Machine vision has left the shop floor and is now roaming the roads and highways of the world. Some trucks in the USA are now being outfitted with it. While embraced as a true lifesaver outside of the USA, insurance companies in the United States are taking a wait and see attitude. Rather than giving trucking companies an incentive to install this accident preventing technology, they instead say that if the accident rate goes down, the company can apply for a policy review. The EU on the other hand is getting the cooperation of its members to use every incentive possible to cut the EU's death rate in half by 2010. AutoVue lane departure warning system by Iteris is a factory-installed option on Freightliner Century and Argosy trucks; Infiniti, BMW, Cadillac, and Buick automobiles. On the trucks, it is a $1,800 option and drivers that have used it, like it. The camera sees a slightly broader spectrum than the human eye does and can see the paint lines beyond what humans can in some weather conditions. If a driver drifts toward a paint line or tries to change lane without turning on her/his turn signal a rumble strip like sound comes from the sound system speaker on that side, giving both an audio warning and directional que as to which side the problem is happening on.



Iteris: Compact camera and computer module

COMPACT
What started out as a van full of equipment eventually was reduced to a palm sized circuit board worth of electronics and installed software. The entire unit fits on the back of the rear view mirror facing forward, looking at the road ahead and interpreting the paint lines. Road and highway markings around the world have been viewed and interpreted by this system. The most challenging paint pattern to deal with was a ninety foot long stretch of cross walk in front of an airport terminal and the system handles it nicely. Discontinuous and faded or missing paint lines have been allowed for. If there are no paint lines, the system gives the driver a system not working warning.


Sun Electro-Proportional Valve With On-Board Electronics

PROPORTIONAL CONTROL
This Sun Electro-Proportional Valve With On-Board Electronics pilot valve, which screws into a hydraulic manifold and has the control circuit board built into it, has the ability to provide 0 to 100% braking pressure to the brake cylinders for soft start and soft stop for the braking system on AGV WENDY DARLING. Individual control of each of the 6 wheel brake cylinder pairs is ideal for creating vehicle behaviors such as stability control, traction control, and other creative solutions that come to mind when individual braking of each wheel is available to the driving computer. Proportional control is an alternative to pulse width modulation of hydraulic oil to the steering ram. The faster the vehicle is going the smaller the corrections to steering angle need to be. While creeping ahead, the steering angle changes can be rapid and large, at highway speeds the corrections need to be small and slow.


Desert Roads, file photo.

DIGITAL MAP DATA - COLOR
An additional data dimension to plan for when designing the guidance system for the US armed forces vehicles is the threat level of each segment of road. This is not a data field used in the usual car navigation map data bases but is an important element in selecting routes for US Army convoys and needs to be taken into account by the routing subroutine. The color-code system that defines the threat levels for convoy routes in Iraq: "Black" means that all traffic on the roads is prohibited; "red" means that a convoy can be deployed in the event of an emergency; "amber" means that the road is clear; "green" indicates that there is no threat at all. This is part of the environment that the AIM Truck AutoPilot with HorseSense software will find itself in when deployed there and other areas of conflict around the world.


2007 DARPA Urban Challenge

Las Vegas to Victorville.  Photo by AIM Team members Linda and Tom Graham.

Posted by Paul Grayson on April 28, 2008 | Comments (0)