July/Aug 2005

Not all trailer tracking systems have been designed for the environment they will be working in, argues Tim Steer of Axscend. He suggests some down-to-earth questions you could direct at any supplier

Trailer tracking is a compromise of three elements: power, functionality and operating or geographic range. It involves some unique challenges for developers - tough environmental conditions, along with the need for a device to be quick and easy to install, yet to provide unattended, multi-year operation.

Any organisation thinking of implementing a trailer tracking solution should decide what is essential and what it can afford to trade off against these three factors. Trade-offs should be exercised with great caution, as too much trade-off could end up extremely costly.

Will the system survive the operational environment?

One of the major challenges for trailer telematics system developers is that a trailer tracking system will be exposed to extreme environmental conditions. In my opinion, it is not enough simply to place a standard vehicle tracking system into an environmentally-rated enclosure such as IP67, which is submersible in water up to 1 metre deep.

Temperature variations and extremes will have a huge impact upon any system or device, and in some cases can render it potentially useless or even hazardous.

The automotive industry requires that electronic components must operate over a standard temperature range of minus 40 deg C to plus 85 deg C. This standard has not been plucked out of the air, but has been set as the ideal through many years of experience of developing reliable components.

Temperature has a particular effect on battery life. Alkaline, NiMh, NiCd and lithium ion all suffer serious capacity issues at extreme temperatures. Some totally freeze, and become useless. Some actually have the potential to catch fire at high extremes.

Radio operability is also affected by temperature. It is exceedingly difficult to design and manufacture a radio that keeps on working over the ideal automotive-industry environmental temperature range. Radio designers must employ advanced temperature compensation circuitry to stabilise devices such as crystals, filters and synthesisers.

This has implications for the GSM/GPRS radio boards now being widely deployed for trailer tracking systems. Generally, these devices have been designed to be worn on the body, and not used within heavy industry such as commercial transport.

A trailer tracking system will be exposed to many other environmental conditions, including dust, shock, sand, vibration and water. Any tracking system supplier should be able to demonstrate that these challenges have been addressed, ideally with some evidence of professional testing to industry standards such as SAE-J1455. This is the standard set by Society of Automobile Engineers (a US-based standards organisation funded by companies such as Ford and GM) for environmental practices for electronic equipment (heavy-duty trucks).

Will the system be reliable in service?

It is essential to have a reliable system that will provide long life and reliable unattended operation. Any advantage gained in improved trailer management and utilisation will soon be lost if the trailer tracking device itself requires a lot of management resource.

A long battery life cycle is essential to a long service life. Again, take care when comparing quotes for predicted battery life. This should be calculated using real-world metrics, because all devices will use varying amounts of power depending upon the environmental conditions or operational demands. Multiple variable drains on available battery power can make battery life predictions difficult.

Solar panels have been adopted by some systems developers for recharging batteries. This will make installation much simpler, but you need to ensure that the solar panels and recharging circuitry will survive the operational environment. For example, if a solar panel gets covered in a layer of dirt, will it still operate effectively?

Even within optimum operating temperatures, rechargeable battery technology can suffer from capacity degradation over time, and therefore require replacement in the field after a matter of months.

Electronic circuits consume more power in hot environments - often as much as 50 per more. Equally, battery capacity can be affected at extreme low temperatures.

Operational needs such as status reporting also affect battery life, of course, and while reducing the number of variables will preserve battery power, it may also limit functionality. That is why it is important to determine the best trade-off between battery life and system functionality for a specific application.

No single trailer tracking technology has been adopted widely enough to be able to prove undisputed product reliability in the field. Generally, the simpler the system, the more reliable it should prove in service. Ask the supplier for evidence of deployment in industrial not consumer applications.

What geographical coverage is required?

Any tracking system must use a mobile data network in order to send its location to a central server, so that you can view the data remotely and position the trailers. Many systems use the GSM mobile telephone networks, but the downside with these is that coverage can become marginalised in sparsely populated areas, and abroad there may be roaming issues.

Satellite communications such as those used by Axscend are an alternative to terrestrial networks, offering a wider geographical area of operation. There are two types of system - 'geo-stationary' and non-geo-stationary. The distinction is especially important for trailer tracking.

Geo-stationary satellites systems typically require a large amount of power because of the high orbit of the satellite, and can suffer a 'shadowing' effect from stationary objects such as tall buildings. There may be a trade-off with functionality to preserve power. Devices that use non-geo-stationary networks for communication tend not to suffer with shadowing, and require much far less power because they are in a Low Earth Orbit (LEO).

What are installation costs?

Installation costs are often ignored, but some systems with lots of functionality may need professional installation that can take up to six hours. The job of coordinating trailers and engineers can have logistical implications, and keeping trailers off the road may also involve a cost.

Physical security of a device is also crucial to long-term unattended operation; does the device or SIM card have a real or perceived value to petty criminals? If one of the tracking components is stolen, the trailer will require attendance.

How will you view position data?

It is becoming clear that Web-based interfaces are proving the most attractive method of data distribution for both small and large transport fleets. This approach is the most cost-effective method of data distribution because the data can be collected on any Internet-enabled PC. In effect, it provides a globally available data portal, without the costs associated with software distribution and support that would arise with bespoke systems installed on clients' own computers.

However, where there is intensive data input by a system operator and there is a requirement for data-rich information, client-based software can provide a higher level of functionally.

Environmental considerations

There are two main issues here, both of which can easily be overlooked. The Waste Electrical and Electronic Equipment (WEEE) Directive could raise the cost of regular disposal of a large number of batteries. With the 'polluter pays' principle, it is important not to forget battery disposal when assessing whole-life ownership costs.

Do also check that the telematics systems will not interfere with on-board electronics such as engine management systems. Some manufacturers have also expressed concerns over potential interference with ABS systems.