- Published in Q&A.
What driver-assistance systems are found in commercial vehicles?
“ Trucks have been using adaptive cruise control systems since about 2005. They can do limited automatic braking when following cars and they can also accelerate. They’re not as widely discussed now. These days we talk more about headway control, collision warning, and fully automatic braking.
What are the main challenges in developing driver-assistance systems for commercial vehicles?
“ In a car it’s simple, the radar nearly always goes at the very front and the camera nearly always goes at the top of the windscreen. In a truck the radar isn’t a problem: you can put the radar at the front but the camera is more difficult. If you put the camera at the top of the windscreen in a truck you can’t see that big space in front of the bonnet.
The other problem is vibration and movement. The movement is enormous – when you brake the whole vehicle moves forward. So instead of sitting in a fairly stable situation as in a car, the technology is actually moving a lot.
The radar and camera systems use lots of inputs; they don’t just operate on what they can see.
They’re fed information from road speed, braking, and by using those inputs they can understand what’s going on. So, if the vehicle starts dipping under braking, it can adjust to that using a different algorithm system.
How are commercial vehicle assistance systems developing?
“ OEMs are picking up second-generation cameras and third-generation radars to take them forward into the era of 2013 to 2016 when legislation becomes tighter. From 2013 new trucks, and from 2016 every truck, must be capable of automatic emergency braking. It hasn’t been decided by how much yet. We measure deceleration in gs and broadly speaking you can go from limited emergency braking, at 0.3g, upwards to full emergency braking which could be as much as 1g.
This requirement has galvanised the truck industry into action to create fused camera-radar systems, because you get the most reliable results with a camera-radar system view.
How important are technologies such as object detection to commercial vehicles?
“ We’re looking at the ability to see fixed and moving obstacles in front of the vehicle. We perceive it as pedestrian detection and it’s actually the most difficult application to develop. We’re then looking at what happens at the rear. Truck operators pick up and drop trailers all the time, so you need a robust system where you can put the radars and cameras into trailers.
For practical purposes mobile systems are more likely, but there is some difficulty because you have to make sure you have a standard fit across vehicles. Rolling calibration isn’t a problem as the technology can recalibrate itself as needed but you have to start with a stable, similar position for the technology to be placed at.
Radar bandwidths have come under the microscope in recent months. How has this affected your work?
“ European governments will outlaw 24GHz in the wide-bands area from 2013. Traditionally companies made radar that operated between 22GHz and 26GHz, but that’ll no longer be legal. So that’s why you need to start developing 79GHz systems – that’s actually a range from 77GHz to 81GHz.
There are a lot of companies with blind-spot detection systems using 24GHz radar. It’s OK but it’s not the future of short-range radar; short-range radar needs a higher bandwidth. So the future of short-range radar is in 77GHz systems. For long-range radar on the other hand 24GHz systems are great. A 24GHz system is usually slightly cheaper because there are applications other than automotive, so the components become cheaper. And it’s much easier to put together. The sensitivity when you’re building 77GHz radar is enormously small; you have to manufacture the whole thing within
15µ, so that’s a third of the width of a human hair. It’s precision, and precision costs money.
How can you make 77GHz radar systems cheaper?
“ Most of the existing 77GHz technology operates on gallium arsenide but companies are moving to